Hi there. Just bought one of these so I will be picking all your brains for information! I am an experienced mechanic but have never dealt with one of these Mikuni carburetors, hopefully there are people here familiar with them.
Got mine last october and I just did the weber swap on it myself. Haven't driven it since the seats are at the upholstery shop, so can't fully comment on that.
If you need a spare Mikuni I'll let this one go for super cheap and I have a Haynes manual if you need some scans.