First I thought it belonged to the Optima Mid Custom Special but when image googling that model I get confused.
I know it's not from Turbo Optima Mid Special as that model have a carbon fiber chassis. And definitely not from Optima Mid Custom as that model have a brownish alloy chassis.
I found this thread with a similar topic but most images are gone:
http://www.rc10talk.com/viewtopic.php?f=30&t=20962
Here is my chassis in question. It's in pretty good shape...
