On Friday, April 28, 2017 at 9:48:53 PM UTC-6, Jonathan St. Cloud wrote:
Out of Truckee there is a club with a DG 505 or 500.

I think you may be thinking of the Hollister based club that relocates to other sites during the season. They own a DG1000 and DG505 plus a couple of singles. That club doesn't train or tow their members, using commercial operators for those services.

A quick look shows there are
64 ASK-21's on the FAA registry.
48 owned by clubs, perhaps others are leased to clubs. One appears to be in a private club.

18 DG-500/505's total
3 owned by clubs, perhaps 1 or 2 leased to clubs.

35 DG-1000/1001
2 in clubs it appears, 19 at USAFA

6 SZD-50
3 in clubs

33 Duo Discus
5 in clubs

Quite a number of the above not in clubs are owned by individuals, some in LLC's and the rest by commercial operators and some in non-profit flight schools.

I'm told the SZD-54 manufacturer isn't bothered with a US STC because they are selling enough in Europe. There is an STC in Canada. I was also told German clubs are replacing their high time K-21's with SZD-54's.

Frank Whiteley