Hello there - I can't find the watch you're referring to on eBay but I would not worry too much.
If it's marked TAG Heuer on the clasp then it's definitely a later service bracelet as TAG started appearing on items round '85 and the watch model dates roughly 1979-1982.
Still, regardless of the brand on the clasp, if it's in decent conditions and foremost if it's the model that fits the watch head nicely, by having the same width as the head at lug end, then I would consider it a plus anyway, since it's very hard to find bracelets that fit nicely that head shape.
Hope this helps. Maybe try posting some pictures if you need more.
Cheers,
Fabrizio