Thanks everybody. It sounds like these aren't overly strong. Once I get it apart I'll give it the ole' 1,2,shove to see if it goes back together...then I'll resort to a replacement. Thanks again for all the tips on starting places.
PK, it didn't dawn on me that freezing could have done it...but that makes sense. The car sat for 24 years, and although it appears they drained the coolant, I don't think you can ever drain the Triumph heater without turning the car upside down.
Karl, the silver one is 1966 Corvette "silver pearl", and the red one I call "brush on red"!?! The red is the absolute worst paintjob I have ever seen. It kills me that they covered over the British racing green to put that orange red on!
Hey JP, is the white in your new avatar the TR3 in it's youth?