Oh, well that explains the continuing problems.
JPC, some of us have a Speedster as a daily driver (like MUSBJIM) and I'm sure there are probably a few more, but not many. Most of us just have it for an evening cruiser or maybe something longer on weekends, maybe to a show or driving event. Mine is a dual-carb 2,110 and I don't drive it daily but it's ready to go whnever I want with minimal tinkering (most of the time) but it does require TLC.
Very few of us have single carburetor cars, but putting the right single carb on it is important. Putting it on a 1915 means that you might benefit from something a bit larger than a 30mm, but I don't know the rest of your engine specs and can't comment intelligently, so a 30mm might be just fine for what you're looking for.
Don't know who's helping you with the conversion, but I sincerely hope that it goes well and you get that reliable neighborhood cruiser you're looking for. You might look up Paul Ellis in Phoenix - He seems to be pretty knowledgeable about air cooled VW engines and/or knows who the good mechanics are. I can't recall his username on here, but @Cory McCloskey might be able to help find him (and he should see this post, too).
Good luck, Gordon