This guy is from the Armour Variants set which was designed by Jes Goodwin and the Citadel Design Team. He’s a 1990 sculpt and shows up in the 1991 catalogue as part number 070270/3. The earliest I can find him in a White Dwarf is March 1990:
The blurb for the Armour Variants goes:
“In the last 5000 years the design of Space Marine armour has evolved through many stages, from Mark 1 to the Mark 8. Many chapters still use all the different types, with the early models regarded as the Chapters Heirlooms. These early armours, once worn by the Chapter’s greatest heroes, have been embellished by the Chaplains Artificers, who create the Chapters equipment and honour badges.”
Nothing on the front or back of the tab on this one, unfortunately.
Undercoat: Vallejo Mecha Black
Blue: Scale75 Art Cobalt Blue, combined with Pro Acryl Titanium White for lighter areas and Scale75 Art Black for darker.
Red: Pro Acryl Bold Pyrrole Red, shaded with Targor Rageshade, highlighted with Bold Pyrrole Red/Golden Yellow
Green: Scale75 Art Spring Green, shaded with Art Black, highlighted with Golden Yellow
Silver: Black Metal, Targor Rageshade, Heavy Metal, Speed Metal
Base: Scale75 Soilworks Reddish Brown around edges, then Dark Mud over that to try something different, then Natural Soil, then Sand in the center, highlight on the rock was Gypsum. The legs were dusted with Natural Soil.
Rim: Vallejo Model Colour Black Grey