I didn't think the samples were that good in 1982. Always thought it was Morrissey on alto. Huh. Do you remember where you read that?
It sounds very much like a sample to me (and not even that good a sample). Vangelis does a very good job of mimmickry but the intonation isn't that of a wind instrument. The E-Mu Emulator was an early but very good sampling keyboard, and Vangelis had one in his studio at that time.