I bought one from the local GM dealer about 6 years ago for the 70 black 4spd car...turned out the original shield was still there and had slipped down somehow and I didn't see it
can't remember if it was stainless or regular but I ended up using it on the 70 black th400 car and it fit fine. So...it wasn't all that long ago that you could stil buy them, and it wasn't much money.
wilma