Linseed oil is a nice oil finish. Cut it 50/50 with terpintine and rub it in by hand. 5 or 6 coats.I also like pro custom oil. It is a blend of tung oil and urethane. You can leave a gloss finish or a satin finish with it. I dont like 100% urethane finishes. They give better protection but the look to much like plastic.

Remove the old finish with a chemical remover like zip strip. Make sure you sand it down. Start with 220 grit. If you like a glossier finish, work your way up to maybe 400 grit or 600 grit. Make sure you use a sanding block or it will look wavy. And be care not to take to much off or your metal wont line up. Also be carefull around sharp corners and angles.