Gold anno, back side machined off prior, strada stamping.
Sounds like, looks like Campagnolo BMX cranks.
I have a set of 170mm in blue with a chainring in blue as well, only area not anno blue is the region of the teeth sides, machined after anodizing.
They came in blue, gold & red.
Got mine from Euro-Asia in 1979 if I remember just prior to my leaving the work for an ice cream store for more money. EA was having a blow out sale, $15. For cranks & ring w/o bolts through the shop. Should have bought pedals & hubs at similar savings.. Oh well.
John Jorgensen Palos Verdes Ca
When I was riding BMX it was Schwinn Fairlady's with welded in tubes for extra strength as the hot ticket. Sold it for $ to buy a Phil Wood bottom bracket and used pair of Campagnolo pedals. At least the priorities were correct.