A product called Renaissance Wax, Ren Wax for short, is used by many gun collectors, and is widely considered to be the premier product of its kind. Its very easy to use, just wipe it on with a soft cloth and wipe it off immediately with a clean cloth. Just Google it for lots of places to buy it. Display boxes are beautiful, but when a gun lays on the same surface for long periods, the material can cause marks or blemishes. If they are kept in a safe or similar enclosure, moisture and temperature control are critical. Forum member Doc44 would be your best source for further particulars on how to store your guns. He can be contacted by clicking on his ID at his post about half way up this page. Good luck.
Bill