I would be very careful grinding the lip of the booster. That is a vacuum vessel. I’ve seen them leak just from age.

As soon as you grind that booster, you’ve lost any factory warranty it might have. I know you’re between a rock and a hard place. Good luck.

Won’t pound

id just grind a little should be fine at the lip sticks up 1/4”.. , but may have a 1/4”-1/2 spacer made too. That’s would cause the bolts and rod to be shorted.. def enough rod but unsure of the bolts just yet . I could notch the bolt holes so the booster would slide up slightly.  but that would cause actuation of the booster to be slightly at an angle.. can’t lower the steering column.. a huge job..  Will probely do a comination of all of all of these.

That sucks!

Any way to slot the steering mounting holes inside, just a little?

If that doesn’t work, I would probably grind a little on both parts. See if you can find the high spot(s) on the shaft.

Any pounding trying to bend that lip may distort the sealing surface, so that’s wouldn’t be a good idea.