I think TVB's Sa Tung Teen actor from LOCH '82 reprised his role in the 1990s version. He also played Beggar's Union Chief Lo Yau Gerk in ROCH '83 and Chui Dat (Chu Yeun Cheung's buddy) in HSDS '86.
I think we've missed someone major in our list so far, haven't we? Hui Siu Hung. As far as I know, he was:
Mo Leung Sword Sect (East School) Leader Tzor Tze Muk in DGSD '81
Chu Chung (Gong Nam 7 Freaks # 2) in LOCH '82
Gung Sheun Tze (Lord of Passionless Valley) in ROCH '83
Wai 1 Siu (Green Winged Bat King of Ming Cult) in HSDS '86
He possibly had other roles in Jin Yong's adaptations as well.
Also not be forgotten is Cheung Lui, who was:
Kau Mor Tze in DGSD '81
Mongolian archer Jebeh in LOCH '82
The Golden Wheel Monk in ROCH '83
Sky Eagle Sect second in command Yan Yeh Wong in HSDS '86
We also had the actor who was Divine Crocodile in DGSD '81, Ling Tze Seung Yan in LOCH '82, Dat Yee Ba in ROCH '83, and an unnamed early possessor of the Dragon Sabre killed in episode one of HSDS '86.
Also, let's not forget the legendary Sek Geen, who was:
Golden-Haired Lion King Tse Tsun in HSDS '78
Siu Yeun San in DGSD '81
Kau Cheen Yan in LOCH '82 and ROCH '83
Another unnamed early possessor of the Dragon Sabre in HSDS '86 (again killed off in episode one).