Sine Cosine

Hello, I have a kit from about 1970 +-1, with the same box art, that has been in a moving box since about then. I had opened it so the cellophane wrapping is gone, and the instructions are missing. Also I apparently pirated a couple pieces from the decal sheet. I am thinking of selling it if I can ascertain its value (and it's worth the trouble). I'll check back for replies. Thank you. PS the box art is the same except for the world map in the lower corner on the OP is not on the box I have.