Since you've read all the threads, I imagine you've seen my replies, so I won't repeat.
I tried researching what years/engines etc. they came on, but with no luck. There doesn't seem to be a whole lot of info about where they came from, except the afformentioned. I don't know any places to find alot of them from, but they pop up on DSMtrader from time to time (which is where I got mine), and Ebay too. Good luck.
'96 Talon TSi AWD - ALLTRBO
'85 Kawi 750 Turbo - SMLTRBO
'90 Camaro IROC-Z - TWNTRBO