i'm glad you told me about it being an 83, because i could find nothing about 81's. the forks have a circular graphic with the bird above an R stamped on each side each side of the top of the crown. the steerer is stamped tange as are the front dropouts. maybe tange-tf. there are no such markings on the rear dropouts. it came with some kind of weird suspension seatpost, but it looks like it might need a 26.2 post. is yours similar? i'm curious to ride this one. i also have an old grand prix that's fixed at this point and makes me smile.