Apologies for this delayed response on all the suggestions provided, my internet is limited and since I'm resigned to being stranded for the indefinite future rechecking this thread had to be low priority. But I appreciate the time you've all taken to try to help. Allow me to reciprocate:
Yes, from the dozens of hours of extensive reading I have done about toyhomes and the A43D, almost no one who owns one or has experience with them thinks they are bad at all. I did a great deal of reading on them before I bought this one, so i knew what I might be getting into, and nothing I read indicated I would run into this problem. I have no worries about a sufficiently executed rebuild/reman going for a good long time, but if I can't get one I'm SOL regardless, and I can't understand why no one wants to touch it.
Thank you for the link, I needed one of these
I will pass this answer along to my dad, thank you kindly. Indeed, from all I read, Toyota put this tranny in Celica Supra, Corsicas, most of their pickups, for over 20 years, and nowhere in my digging did I see any consistent reports from people which would indicate they are bad trannies. I absolutely believe they are more than up to the task pulling these mini monsters. Sadly, none of the rebuilders in the areas within reach of me agree.
I appreciate the tip on the alternate rebuild manual--we already have and read the ATSG rebuild manual. It was inadequate for my dad (he is highly dyslexic, the instructions are vague, and the illustrations are simple drawings, all of which make him unwilling to use it). He is an incredibly fussy gotta-get-it-RIGHT person, got his living as a highly skilled tool & die man before computer operated machinery took over that field as well as being a certified mechanic, and he places a great deal of importance on ensuring he isn't making me a bigger mess by attempting the rebuild himself with instructions he can't make sense of--he really needs the detailed illustrations we expect to be in the official rebuild manual... He has rebuilt numerous manual transmissions (Pontiacs and Fords mostly) but never an automatic, and he was ready to tackle it until another retired tranny rebulder told him the A43D is not an automatic tranny to try learn rebuilding automatic trannies on. Now he's spooked. I just tried looking and can't find an ATRA for the A43D ... Also looked into Chilton and Haynes, but all the reviews complain they are too broad. Per linda's prompt I took another read through the excellent post from spungo on his 1986 A43D rebuild and saw he recommended the 1993 OEM manual so I did a price check on that and it's for sale for about $30. Looked back at the 1986-1989 manual for $164 just to see if the price had gone down and if the pictures provided are for the actual item then it's a false listing anyway--it's actually offering the 1993 copy, lo and behold. Pretty scammy if you ask me, though he may not know he's made the error. I am going to purchase the 1993 and just work on convincing my dad it is the best option we have. Especially for only $30 vs. $164 when it wouldn't have even been the "right" book, hahaha.
I still need to explore as many backups as I can though. I am in MidWest MI. We've called numerous places as far away as Jasper Transmissions in Indiana and the only guy so far willing to touch it won't give us a quote without opening it up first for a fee, said it could take an indefinite amount of time because any parts needed outside a rebuild kit are special and hard to get, and said nothing to the effect of giving a warranty. He's also 100 miles away so I'm going to have to be absolutely desperate to pay him $200 just to tell me it could be a $4k deal with no guarantee. If you happen to know someone in this general vicinity you'd recommend I call, I would be grateful for a referral! I will pass along what you've said to my dad--if I can get him to trust the people on this forum who OWN them over some jerks who don't actually know this transmission it might make all the difference for him to try to do this himself.
Your information has been incredibly helpful, and any further assistance you can provide re: rebuilders will be greatly appreciated as well!
Oh, and I currently still only have my burnt up tranny, Autozone refused to fulfill my purchase from them and gave me a heck of a time even getting all my money back. They still have the tranny they sold me listed for sale on their website in fact, and at this point I've filed a complaint with the BBB to try to make them remove it or give me the darn thing if they do actually have it since I can't get anything but an unknown-condition used one anywhere else (plus all of those that are on offer have no warranties or the warranty is void if you don't have a certified tech at a licensed facility put it in, and I'm not paying what could be more thousands for installation when I don't need to, my dad has that part covered no problem if we don't go with rebuilding this one).
I can't tell if there was a link or photo embedded in your reply, but if you mean the old long post by spungo then I am very familiar with it--it was the first and most helpful information I have found online to try to do the rebuild, really awesome he took the time to put that up here for people like me in the same boat and I am grateful to everyone else who contributed to the extensive conversation there. Plus the photos are a godsend. At your prompt I did take another look through it and found his recommendation of the 1993 manual, and since his rig was also a 1986 and he said the 1993 manual was better than the 80s manuals I figured I could trust his judgment on that. So I just purchased a 1993 OEM A43D tranny repair guide for just under $30. Turns out the 1986-1989 manual for $164 is actually a 1993 anyway, mislisted and overpriced. Fancy that! So thank you very much, I have read way too much about this tranny now now to keep it all straight, and without your pointer here for me to go back to that post I would still be stuck on the repair guide problem.
You folks are all just lovely, I can't tell you how grateful I am for the time you've taken to offer me info and advice. I'd probably be way more lost than I currently am without this forum. <3