I'm listed as a member of both the ILGPC, and CGPC (ChicagoGrandPrixClub).
I've been to one "mod" day (fuel injection cleaning at Casper'* Electronics), and one annual meeting thingy with ILGPC. I used to post there often....but after a year of posting, it became evident (through little things) that pre '97 GPs are either uninteresting, or unwelcomed to a good portion of the members there. So, I haven't posted there in some time, and don't consider myself a member of ILGPC, anymore (can't find a way to unjoin, or I would have by now). Don't get me wrong, I met some pretty cool folks at the meeting, but the over-all vibe I was left with on the forums made it seem my posting there was pointless.
I'm still active on CGPC, and in fact, put together 3 local Gen I w-body.com meets this year (4th one coming up at the end of this month), for which, several members on CGPC took me up on my invitation which I extended to the club (including Mr. & Mrs. President of the club, on one them). I've also been to one mod day, and one annual picnic with them. Nice group of folks who don't look at GPs as a competition between Generaton I and II (decent mix of both on that club, where as I was the only gen I owner posting on ILGPC; the 3 or 4 others stopped posting before me).
.....of course, I don't own a Bonneville, so I don't know how usefull this info is....