I've never seen a steering wheel for a 70 Camaro on any other vehicle.
The Chevelle steering wheel in the OP's pic looks like a 71-72 Camaro wheel but they are a soft sort of rubber whereas the Camaro wheel is a hard plastic or acrylic (?) and shiny. They crack like hell all over the place. The Chevelle and other GM vehicles with that rubber wheel will get sticky, too like the 4-spoke wheels (optional on maybe 71 and 72, standard after 73 then rope style). I have/had all four types of wheels.
EDIT: Regarding the 4-spoke wheels, I meant to say standard on 73 and after then rope style. I've had those Chevelle wheels, too and they would literally have sweat beads on them from the ooze.
I've kind of wondered if the 1971 Camaro standard wheel (and perhaps this one here also) were not very close if not that same as the 1970 Camaro wheel except for the horn piece with maybe one small, easy to overcome difference. The 1970 Camaro wheel had 4 holes in the cross to attach the horn cross piece (thus creating a specific part number), whereas these other wheels only had two in the same places as the outer two on the 1970 wheel. It may be very easy to locate and drill the missing holes this would open up many more possible wheels to replace missing-cracked 1970 wheels. Someone with a 1971 wheel could maybe verify this theory with a 1970 horn piece.
EDIT: Nevermind. they do look a little different where the edge of the cross piece is. The 1970 wheel has less curve to it.
The NK2 (NK1 in 1970) was a no show in 70. Never actually released, but you see them often, usually when the original standard wheels are cracked and they can’t find a uncracked replacement. It was the “Corvette” style aluminum 3 spoke wheel with the grip area vinyl coated in 1970. In 71 and later it was the 4 spoke all vinyl wheel that was common on Camaros