Some great stuff showing up here.
Have been thinking of how to come up with a team of mixed-TL, mixed culture characters - would just love to see someone from 1700s Earth out and about in space with some non-humans and humans of varying tech/skill level. Could well imagine that, while his grasp of certain tech would be sketchy, he'd have survival skills that a some of the higher-tech characters would not. They might be lost without electricity while he's happily scraping flint and steel to light a fire.
Mixing different tech levels could be fun from a perception angle as well - 1100's character surrounded by C20 stuff may well view it as magic. Even if you explain it's machinery, (s)he's going to be in awe that it is so compact and does not require huge water wheels to drive it... Now try to explain electricity and batteries...
1700s people would recognise certain things - watches, spectacles, firearms, TV would be an advanced "Magic Lantern" and it's not a big step to work out that "camera" comes from "camera obscura" - just more advanced. Even electricity would be explainable - the miracle would be what can be done with it. Move up to the late 1600s/early 1900s around the time of Jules Verne and H.G. Wells, acceptance of high tech things would be higher - especially amongst those predisposed to reading the budding "Scientifiction" genre. They would readily accept machines that fly through space and would be knowledgeable enough to know why you don't just wander out the airlock mid-flight to have a pipe or cigar...
Though they might be disappointed to discover Mars and Venus aren't as well-populated as ERB imagined (unless, in your game, they are).
Plenty of scope for fun role playing.
Perhaps it's time to dream up a Time-Travel game...