Nice kit! It's a higher end D series kit. D20 is 20/12/14 and the D22 is 22/13/16 so it's a cross between the two. The wrap is called blue willow and late 60s/early 70s is about right, although I'm leaning towards the early 70s with that tom mount (the earlier ones were a simpler, more traditional rail attachment I think). Really nice quality drums. There is loads of info on these kits on this forum if you have a search around.
True.
Funny it has the ''C'' series steel hoops. Could be aftermarket hoops.
Lovely drums. Keep on to them. They sound amazing.