This rarity was originally issued as a set in 1989 in White Dwarf 118 and re-issued in the 1991 catalogue. It does however belong in the Oldhammer Rogue Trader era of Warhammer 40,000.
The figure itself is fully complete with all throne pieces and arched back. It is however missing the Magus Advisor to complete the set. If I had that it would be in our Collectors Club.
Still a great piece to collect or as centre piece of a diorama or conversion.
Catalogue image from www.solegends.com.