What did that Weber come off of? If it was anything other than a well-used B18, the jetting may not be exactly what you need---and rejetting a Weber is (in my experience, at least) a long, aggravating process of trial and error. I've had them before, on a couple of 140s, and found they were better than SUs in only two areas: Cold starting (with manual choke--don't know about electric or hot water type) and a steadier idle. For driveability, properly set up SUs are way better, and gas mileage seemed to be about the same.

I would not trust the 10+ year old rubber seals (or the accelerator pump diaphragm) If you're going to do it, do it right and get a rebuild kit. I think IPD used to have them, or try International Auto Parts, in Virginia. They are the equivalent of IPD for Italian cars, and have a lot of Weber stuff.