I believe they are. Check on the Hamtramck Historical site in the trim & option guides as there may be a difference in which cars would get a full horn ring and which would get the 2/3 version. IIRC, RRs got 2/3 ring. '69 RR had its own center cap featuring the bird.
I've never seen an original base-interior RR with an upgraded steering wheel that I could confirm was correct, but the options/trim pages on the HH site & the car's line sheet ("broadcast sheet") will tell you what the car should have. Decor Group cars got the Satellite or upgraded woodgrain wheel, and to the best of my knowledge not the base (Belvedere) wheel.
