If you hunt around on the internet, you might be able to find the 1st edition Space Hulk Bible. It’s a collection of everything Space Hulk. Imperial Guard, Necrons, Space Marines, Eldar, Tyranids. About 120 pages worth.
Here’s an explanation from the author, from Boardgamegeek:
“When I put the SHB together, my aim was to condense all 1st edition rules into a single volume. It gathers the rules from the core game, Deathwing, Genestealer, Space Hulk Campaigns and various White Dwarf issues. Some edits were made but these were kept to a minimum. A few new diagrams and gameplay examples were added to better clarify some rules. I also included some unofficial rules for troops other than Space Marines. It was a mistake on my part not to better identify these as optional house rules. I also regret not dividing the weapons pages into official and unofficial sections. ”
I must have a later edition, as it adds Necrons, but everything else is first edition. We’ve played a multiplayer game with all of the races involved years ago and had a great time!