465 was made from 1946 until around 1973 or so then came the Fox model from the early 70's to sometime around the early 90's then came the 527 models that are currently made.
The early 465's are worth a premium in my opinion, the cheapest model is the fox, I.M.H.O. The 465's have double set triggers, the FOX had double set triggers on most , and the 527 is single set triggers.