These have been selling at auction sites over the past several months for $45-$75 plus shipping based only on pictures and without any information at all about their working condition, so all-in you probably got a great deal. I'm just finishing up work on cleaning up a 1951 2Y series Skyriter myself, and I really like its typing action. Don't throw away the spools if it came with them as they're non-standard and slightly smaller than the ubiquitous universal spools. This being said you can buy the standard 1/2" ribbon and manually spool new ribbon onto your existing spools. Mine didn't have spools at all, but I found some replacements (with ribbon) at https://www.ribbonsunlimited.com/. Take note that it's not a bichrome machine, so you can buy a single color ribbon.

There are two screws that hold the chassis of these into the bottom of their case. They're hiding just underneath the carriage. Once removed, the typewriter lifts back and up and out of the base. You'll find the serial number on the right hand side of the frame underneath the platen and can use it to date your machine with the database: https://typewriterdatabase.com/smithcorona.86.typewriter-serial-number-database. Based on appearance alone, I'd place it as a 1960 3Y series based on the color, the badging and the white keys. You can look at others' individual models and notes at https://typewriterdatabase.com/Smith+Corona.Skyriter.86.bmys. If I'm right about the date, Richard Polt has online manuals available for the 1960 as well as others at: https://site.xavier.edu/polt/typewriters/tw-manuals.html.

https://www.youtube.com/watch?v=xjumGF9NFE8 is a pretty solid cleaning primer. Searching YouTube will uncover some potential additional advice in addition to what you can find at https://site.xavier.edu/polt/typewriters/tw-restoration.html or in his book. I will say that in cleaning mine, the mineral spirits dissolved the glue holding the felt on underneath the typebars, but it was in terrible shape anyway and needed replacing. The foam strip underneath that felt came out unscathed without much effort on my part to be careful with it.

Most of the mechanics are pretty basic and easy to clean/service. Unless there's something dramatically wrong with it, you could very likely clean and service it yourself. (As an example, I had to re-slot the mechanism for the margin release which was almost too easy.) Even the mid-level repair issues for it can be easily found on YouTube if you're handy with a screwdriver (Joe Van Cleave and Phoenix Typewriter in particular have several model specific videos on the Skyriter). The platen and rollers come out fairly easy with a small screwdriver and removing one half of a spring on the back of the paper tray. This gives you great access to clean the escapement from above as well as to potentially send them off to JJ Short Associates for replacement via https://www.jjshort.com/typewriter-platen-repair.php. If you're less handy, Polt's website has a list of repair shops around the world that could clean/repair it for you.

Good luck with it. I hope you like yours as much as I like mine. They're one of the most solid and sought after ultra-portables out there.

How to Change the Platen and Feed Rollers on a Typewriter - The Smith-Corona Skyriter, Part One by [[CreateX3]]

Typewriter Video Series - Episode 175: Skipping Skyriter<br /> by [[Joe Van Cleave]]

Smith Corona Skyriter Shift Repair, Ring & Cylinder Adjustment for Even Quality Print by [[Phoenix Typewriter]]

My first "ultra-portable" (Skyriter 1955) by [[Just My Typewriter]]

55 had an integral cover versus later versions which had bags.

Typewriter Video Series - Episode 143: Rocket Versus Skyriter by [[Joe Van Cleave]]

Typewriter Video Series - Episode 121: SCM Skyriter by [[Joe Van Cleave]]

Joe likes this better than the Hermes Rocket. Solid ultra portable.