Welcome to the forum Toniaus. Both your keris have some real age to them, but i will stop short of pinpointing any period. Determining the tangguh of any keris is tricky in hand and extremely difficult based merely on internet photos. Some might offer their opinions anyway, but i would not chisel them in stone if i were you. I can see that yours are not modern keris and i would even guess they might be as old as 18thC or more (though i could be wrong).
This keris has one of the standing pamors or pamor adeg. It is indeed dressed in the formal (ladrang) Surakarta form so Solo is the probable origin. I doubt the green spots indicate copper unless you are referring to the metal part of the sheath (pendok), though that looks like it might be silver or some silver alloy (though mamas is more common). Have you tries a polishing cloth on it?
Blu Erf gave you some good advice, but i wouldn't be so hesitate about recommending more elaborate methods if the oil and brush doesn't fix your rust problem. Here's a link that might help you:
http://www.vikingsword.com/ubb/Forum1/HTML/000717.html
You might not want to go as far as the staining aspect discussed in this thread, which you would want to practice on some unimportant blades first i think, but the cleaning method is fairly safe and fool-proof and will remove deeper set rust.
