Thanks, all.
Spent my birthday at the PCA High Performance Driving Clinic... kind of an intro to DEs. (I have no intention of doing DE's, just wanted to do this event.)
Had a blast. Skidpad, threshold braking, collision avoidance, and a couple of afternoon lapping sessions. I was the only pre-80's car there, most were new Boxsters, Caymans, and 911s, including a couple of GT3s. Under the circumstances, the 914 held its own. Even with stock 2.0 and stock-size skinny tires, nobody caught up to me in the twisties.
Did a lot of pointing people by on the straights, however...
I was also the first (possibly only) to take my car off-roading during the lapping sessions.