Got the 1973 made, original model 4" SW 66 at the auction in November. I was going to immediately sell it, but since putting in a new hammer spring and running a couple hundred rounds through it...........it's not going anywhere. Sorry.
You might keep an eye on the auctions (the real auctions). They're selling a boat load of 4" revolvers at the Rock island Auction, trouble it you'd have to buy 3 or 4 of them at once.