Pictures please? It will help with ideas, also we like them.
Take a look at the stickies here on cleaning old machines and watch Muv's videos if you're new to vintage machines. Remember no harsh cleaners or solvents or you will destroy your decals. Sewing machine oil is safe and effective. I'd clean the machine, oil it and turn it over by hand a few times then make sure the wiring doesn't have any bare spots and looks safe then plug it in.
If the rest of the cabinet and irons are there it won't be too hard to find the parts you need to return it to treadle mode, but really it's your choice. Which do you prefer: treadle or electric?
Congrats on your new machine!
Rodney