The only remaining players from the glory years that I haven't yet seen photos of them in action for the Albion (as opposed to posed pics) are Moshe Gariani, Glen Geard and Chris Rodon. I suspect these will be even harder to find.....
Definitely not Pearce as he made his debut for Brighton at the start of the relegation season in 1982/83. Looks like him though.
I'm pinning my hopes on it being Jacob Cohen. It's been a long search to find any action shots of his time and judging from this thread, it sounds like it might be him...