If your recording is of the first ever ITV broadcast of Star Wars, then it'll be from 1982.
I've just dug out some clippings I saved from the TV Times way back then, and its dated for the week of 23-29th October 1982, with Star Wars being shown on the Sunday at 7.15.
Seeing these old, dog-eared pages makes me wish i had a scanner. I'll try grabbing some shots with my digital camera, cos these TV Times extracts make interesting/nostalgic reading.