This guy is from the Armour Variants set which was designed by Jes Goodwin and the Citadel Design Team. The blurb for it 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.