This metal Warhammer 40K miniature is one of the Armour Variants – this one is Iron Armour 1. It’s a 1991 sculpt by Jes Goodwin and appears in the 1997 Legends catalogue as part number 070270/15.
I got hold of this chap in April 2026.
Rogue Trader Space Marine in Mk3 Armour 1