Rat,
number 22 is a KRRR, made from around 52 to 57, and still raced thru to around 71 when the XR came out to replace it.
If you want to see them in action, jump over the mountains and head to the Bonneville Vintage GP, at Miller Motorsports park, Tooele Utah..on Sept 4, 5, & 6th.
I might get there myself, got great pics of them bike last year.