Dave, I show that cover to be used on a lot of cars as well.
3831527 (Group 0.679)
1966-1968 Chevelle W/P.G. (396)
1967-1968 Camaro, Nova W/P.G. (350)
1969 Chevelle W/P.G. (350)
1969 Camaro, Nova W/P.G. (350) (exc. 2/BC)
Probably used even later (and on other models) but my book only goes to 1969. READ THIS THREAD...HERE'S
one on ebay from a 69 Impala (not sure about the engine though. Doesn't look like the one in the link above.)HERE'S
a chrome one (not sure about the application on this one either. Might be one of those "one size fits all" kind of things...)
Looks to be a hard item to find. Good luck...