I'll preface this by saying I know absolutely nothing about typewriters (for right now). I got this one at a garage sale when I was a kid, said I'd fix it up and use it, and then abandoned it to my closet for the next several years. Obviously it needs a good cleaning, but as far as I can tell it's still in working order (except for the spacebar which doesn't move the carriage, unsure if that's something that needs fixing or if some switch is flipped somewhere that locks it in place). EDIT: spacebar works fine, it just doesn't depress all the way while in the case for some reason.
I recently remembered it existed and decided to finally do some research to see about doing some maintenance/repair, but I can't find much on this model. I only found one other post on this subreddit about it, and they couldn't seem to find any info either, besides the fact that it looks pretty much identical to a Remington Quiet-Riter. Does anyone know if this model has any significant differences from a Quiet-Riter? Does it even matter that much for when I go in and do maintenance? Again, not super familiar with typewriters, so I'm not sure if there are different considerations for different models or if the process is more or less the same for all of them.
Any info is appreciated! Thanks!

Check your serial number at https://typewriterdatabase.com/remington.42.typewriter-serial-number-database to help place it. It looks like it may have been on the border of the end of the Quiet-Riter/Letter-Riters and the 60s version of the Remington Monarch https://typewriterdatabase.com/Remington.Monarch.42.bmys.
Resources for cleaning available at https://boffosocko.com/research/typewriter-collection/#Cleaning,%20Repair,%20&%20Restoration
I can't seem to find the serial number on the page (ERM459904), though it's entirely possible I could have just missed it. I do appreciate the cleaning resources though!
You're sure it's ERM and not TRM? You won't find the specific serial number on the page, but should find the prefix and where the number fits. If not, upload photos of it (including the S/N) and the details by creating an account. One of the experts will help determine how unique it is and where it may have fit in the manufacturing timeline.
There's a similar ERM machine at https://typewriterdatabase.com/196x-remington-monarch.9097.typewriter
I found that one as well, it does look similar to mine. I'll make an account and upload the photos, and update this post if I find anything out!