My initial though is to replace the levers with Hex Screws.

Yes, not totally QD but I would not go stuffing around any more with more machining, replacing metal etc etc.

I think you are over complicating the whole thing.

How important is it that you have QD bases ?

To be honest, I have never had to remove a scope and
revert to iron sights mainly because I use low powered scopes
and even at 15 yards where all I see is a furry mass charging at me, it was still good enough to get a shot off and stop them both.