Ok, so I've taken all the screw ears down a tad with a file. Both halves of the carb now mate much better than before. However, the end of the horn where the fuel comes in there's still a small gap. But I think the gasket may fill that void. If not, then I'll double up on the gaskets that I cut (1/32").
Interesting - during this process of filing there was a flashback to my days as a kid with my first ratrod. I seemed to remember going through the same thing with warped Rochesters and filing them down. But it's been so long that I can't remember how well it worked.
Let you know how it works out when it's back together..