I know Beach Grove Firearms would gladly welcome your NFA items.
What kind of class three are you thinking of? Most places wont know or care if you are shooting an SBR or Serbu Super Shorty. Some places might be a little concerned with suppressor use. Full auto is obviously the biggest concern. You wont be able to shoot full auto at any of the DNR ranges, and many private ranges have restrictions on it as well.
As far as ranges go, I will let someone more local to you answer that. I know Beach Grove Firearms would gladly welcome your NFA items.
Question is can you afford to shoot full auto these days.
when I lived in Chicago we used to go to Buffallo Rock in Ottawa Illinois. The whole 9 yards would show up out there from tripod mounted mgs to post 86 dealer samples. havent been there in years.
just east on 80 about 3 hours from st joe county, thereabouts.