I have been doing some research into some actors that may or may not (but probably may) have been in Star Wars.
1. Robert Clarke. Apparently an English actor who portrayed Wullf Yularen in A New Hope. According to Aveleyman, may have been called Robert Carrick, or Robin Clarke. Sometimes mistaken for the American Robert Clarke (1920-2005) who was father to actor Cam Clarke of Dogtanian and the Three Muskehounds fame. The younger Clarke also portrayed O-Mer in The Clone Wars. It would be interesting if it is possible to establish a birth/death date(s) for him, or even a name. @Dat1899 has been a help in this, but there is still more to uncover.
Figure 1 - Robert Clarke (Carrick?) as Wullf Yularen in Star Wars (1977).
2. Jules Walter (or Jules Walters) allegedly portrayed Rennek, a Nerf Herder named for Kenner in Return of the Jedi. I have found two Aveleyman pages for him, it seems:
https://www.aveleyman.com/ActorCredit.aspx?ActorID=22908
https://www.aveleyman.com/ActorCredit.aspx?ActorID=190638
Both of them seem to be of him. The latter credits the role of Rennek and, confirmed via the Book of Face, his nationality. It also seems to reveal that he was born in July 1929, which is news to me. The former is of a Jules Walters who is sometimes credited as Jules Walter, who looks somewhat like him. Maybe they are the same person? It would be nice to establish a full birthdate for him, and whether he did actually portray Rennek.
Figure 2: Allegedly and entirely probably Jules Walter(s) as Rennek in Star Wars: Return of the Jedi (1983).
3. Roger Williams. This man portrayed an Unidentified Stormtrooper in A New Hope, becoming the oldest actor with a confirmed age in Star Wars.
https://www.aveleyman.com/ActorCredit.aspx?ActorID=86842
This page provides a picture as well as the credit, more or less debunking @Dat1899 's theory that he was fabricated at a later date. There is still a chance that he was, but with so much evidence to the contrary, I think it is safe to say he existed and appeared.
All I know of him at the moment is that he was born on 6 March 1900, and died on 27 August at some point in the 20th Century, possibly 1975. I do not know whether this makes it possible for him to be in Star Wars, it may do, but the date could be wrong.
Figure 3: Roger Williams as Bellamy Meraulton in Meet Mr. Callaghan (1954).
4. Ian Selby. Seemingly in the business since the 1940s, Ian Selby was a somewhat of a veteran actor by the time he portrayed Hurst Romodi in A New Hope, but then suddenly disappeared out of film credits in their entirety until 2012, and even then it was archive footage. Hardly anything is known about him outside his film roles, and it would be nice to track him down, wherever he may be.
https://www.aveleyman.com/ActorCredit.aspx?ActorID=103470
Figure 4: Ian Selby as Hurst Romodi in Star Wars (1977).
5. Henry Roberts. Portrayed Anj Zavor in A New Hope... Which is just about the only thing I can say about him. He appeared in 3 other films (Gang War, On the Bus, and Top Secret!), all between 1971 and 1984, bar for Gang War, which was released in 1940. It would be interesting to know whether he is still alive, and if not what happened to him.
https://www.aveleyman.com/ActorCredit.aspx?ActorID=119108
Figure 5: Henry Roberts as Anj Zavor in Star Wars (1977).
If anyone knows anything about these actors, preferably in the fields specified, or if anyone is willing to attempt to aid me in finding it out, please let me know in the comments of this post. Thank you in advance.