Watching the Blake's 7 episode 'Dawn of the Gods' the other day I noticed in a pile of scrap that Villa was looking through the head of IG-88, one of the Bounty Hunters from The Empire Strikes Back. The prop was originally seen in the cantina in Star Wars behind the bar, and was made from a Derwent Flame-tube from an aircraft engine.
An IG-88 body can also be seen on Bespin in the scene where Chewbacca is recovering the parts of C-3PO from the Ugnaughts in The Empire Strikes Back.
In the first series of Blake's 7, the control panel of the spaceship The London was salvaged from Scaramanga's laser gun from the James Bond film The Man with the Golden Gun and was amongst many props that the BBC did buy from Pinewood studios, so there's a fair chance that the Blake's 7 prop could have come from the cantina set when scrapped if the BBC did a similar deal with either Elstree or Shepperton Studios. I remember reading an interview in which the BBC guys would go through the skips at the studios were Space 1999 was being shot looking for stuff they could salvage for the likes of Doctor Who.