He’s a Mark Copplestone sculpt, part number 401207 with the legs to suit a horse. White Dwarf #111 gives his year as 1989 and he can be seen in that issue:
Rogue Trader Imperial Army Rough Rider Commissar
He’s a Mark Copplestone sculpt, part number 401207 with the legs to suit a horse. White Dwarf #111 gives his year as 1989 and he can be seen in that issue: