Couple of things:
the 600 242 is the casting number of the part....just coinkydink that it matches your car!!!
Those Allen fasteners look like they would work well as you can still loosen them and get the whole mess off, with the shaft in place? Understood that they must be in place before shaft is installed....
My old steel bracket had just enough clearance in the bearing holes that I could tap the shaft in and out with a plastic mallet. That is the only saving thing that allowed me to change bearings out in the parking lot in Vegas one year! (Blew a front bearing....cheap or incorrect bearing seals I believe....new one looked much better! Better seals.)
If I can get conventional Allen headed bolts to work, I'll go that way... if not, then I like this idea too!
Spoke with another member last night at the meeting that is going to try some sort of double sided stud, to secure the intake manifold, and allow removal of the shaft and bracket without breaking the seal of the intake gaskets.....allowing water to enter the intake ports and the engine valley!
Certainly a unique and challenging feature of these cars!!!
Steve