The following is based on Van Buren and has not been confirmed by canon sources.
Sid is a member of the Rusty Hooks in 2253 and is tasked with figuring out a way to make the sub-reactor, of the Bloomfield Space Center, more efficient, as well as scavenge the grounds and create something useful – what that something could be, no one ever explained to poor Sid.
Sid is not a gifted man in either looks or brains. He was always the guy who hung out in the back, never trying to stand out from the rest of the pack. The only thing that kept Sid from disappearing into obscurity completely was his mechanical and science skills. Now, no one would confuse Sid with a bona fide mechanic/science expert, but he did show an above average skill with such things. If he tinkered with something long enough, he usually figured out how to get it to work – mostly.
For the longest time, Sid was content being the forgotten Rusty Hook. He coasted from one raid to the next, hiding behind the braver (or dumber, depending on how one looked at it) warriors during a fire fight, always assuring himself the minimal respect of at least being in the fray, if not in front of the fray. Sid might have lived his entire life coasting on the coattails of his mates if it were not for the unfortunate abduction of Jillian McKinley, the Rusty Hooks' true mechanic and science expert. When Jillian was hauled away by a security robot during a raid, and was never seen or heard again, Kyle appointed Sid the resident mechanic. That would have been just dandy for Sid if Kyle never found Bloomfield. However, now that Bloomfield was the declared hideout for the Rusty Hooks, Sid actually has to work and show results. This put a hamper on Sid's preferred lifestyle of sloth and mooching, so Sid is none too pleased with his current predicament – a predicament exacerbated by the fact that Kyle is not pleased Sid only got the sub-reactor to work at 45% efficiency, and has yet to produce anything "useful" from all the shit that's laying around Bloomfield. Sid knows that his time is limited if he does not produce something for all his work, and is pretty desperate for any help.
Sid will be fairly short with the player at first, but will lighten up if the player shows interest in helping Sid attain either better mechanical skill, finish his little projects, or return Jillian to the Rusty Hooks so Sid can fall back into obscurity.
Sid has not appeared nor is he mentioned in any published game. He was to appear only in Van Buren, the canceled Fallout 3 by Black Isle Studios. It is not certain if he will appear in any future Fallout game.