Colt did not make the rifle. Sauer made it for them.
Try e-gunparts.com
Contact Colt, on line aucitons.
Contact Sauer.
Contact Uberti Customer Service through their website and get an owner's manual. You did not say what MODEL rifle you have.
Best left to a gunsmith
Price, the 92 costs more
You will have to call Sig Sauer to find out
What is the age of a Colt rifle serial SLD25319
I don't know how much exactly but a lot. The fact that it is from Sauer (now part of Sig-Sauer) and that it is a fine and now discontinued sport rifle will make it VERY valuable. Unless of course it is in absolutely terrible condition.
You will have to call COLT to find out.
e Ask a gunsmith for help