Yeah, a VIN inspection is always required when registering a vehicle purchased from out of state. It'll take 10 minutes.
Not around here.
No one will look at your VIN, even if you're trying to fix a salvage title to a rebuilt title.
I grew up in the northeast (NY, MA, CT, NH) and then in 1973 I moved to GA.
I love my friends in the Northeast, but the level of government scrutiny and control on every aspect of life up there is beyond anything that most southerners would put up with.
It is changing as northerners migrate to the south for new opportunities, and then when they come to the new environment they immediately begin to try to change it so that it reflects what they left.
Sigh....
As for the antique, we have a specific antique classification for motor vehicle registration, and the antique designation is inexpensive, but technically limited to "weekends and transport to shows." I've never seen any enforcement though.
The old Matchless single will be fun to own. I sure enjoyed old British bikes ... and I should have kept some that have now doubled since I sold for customers in Japan and mainland Europe (British expats remembering days gone by). A good, reliable alternative to an antique is one of the early 21st century Triumph Bonnevilles. They were carburetor, had 790 cc air cooled vertical twins, mechanical tach and speedo, cable clutch, and were actually built in Britain. If there's not a lot of nostalgia in those 2001 to maybe 2006 Triumphs, there's none anywhere. Parts are readily available. They're reliable starters and runners. They don't leak oil. The brakes and suspension are quite good compared to their mid 20th century predecessors.
The old Matchless may kindle an interest. FWIW, there are folks who ride the Bonnies across country, adding a whole new level of nostalgia for those of us who hopped on in 1965 and headed to the opposite coast or border.