This guy is one of the original C100 Space Marines released as a squad. He appears in the later 1991 catalogue as Bolt Pistol and Chainsword 070121/38.
He’s a Bob Naismith sculpt, like the other C100 Marines.
Vintage Metal Games Workshop C100 Space Marine Death Squad aka Bolt Pistol and Chainsword 070121 38
Pingback: List of metal Space Marine models – nostalgia force! – Angry Griffin