I don't know about the complexity of a Weber versus an Aisin, but I just rebuilt this 1970 carb. It's my second one, the previous being an Aisin carb for a 2F/FJ60. With some good instruction, like a manual AND some YouTube videos, it's not hard at all. I had to file down some screwdrivers and you might need a $10 protractor from Ace Hardware to measure butterfly valve angles, but it's pretty easy. Cross your i's and dot your t's every step of the way and you're good.
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(There are some nuances in setting the carb up properly, and that's why the usual experts here excel at what they do. Not taking away from them. The basic tear down and rebuild can be straightforward with some patience though.)