There are many bad rebuilt carbs for sale (including rock's) and many people are disappointed after spending a lot thinking that will solve their problem.
If it is leaking while idling, the bowl must be overflowing - either the float sunk of the needle has junk in it. Both are easy to trouble-shoot and fix. I would try that first. I haven't worked on a 1945, but it looks like you can remove the top fairly easy on the car, and probably re-use the gasket. Stuff some paper towels down the throat in case you drop a screw. If you want to go further, buy a rebuild kit and take it off for some bench work.
Of course, if you can find a new carb on ebay cheap, that might be best. I got a new Carter BBD for my small block for $25 and it works fine. Slant carbs are rarer. I think many would work. People love the Holley 1945. I have a Carter BBS on my slant, which seems fine. I don't recommend the Holley 1920 due to personal experience with 3 bad rebuilt ones. There was a Holley Economizer carb in the early 80's. I see new ones on ebay occasionally.