find out who made gun and age

Question
I have a ranger o/u 12 guage model 103-10- serial#R10093. I would like to know who made the gun and also the year of production.

Answer
Tom. Your Ranger Model 103-10 was made by Marlin Firearms for sale through Sears retail stores. It is actually a Marlin model 90. According to the serial number you have provided, R10093, it was made in 1957-1958. Some of the firearms made by Marlin overlapped portions of two years. For example, the serial number beginning with the letter S covered portions of 1958 and 1959. The letter U prefix covered from August 1960 into 1961.
You do not describe your guns appearance, but I will give you a few facts about the general appearance of the model 90. From it's inception to 1949, the barrels were divided by a vent. After 1949 the barrels were made together without the dividing vent.
In general, the barrels varied from 26"-28", with muzzle chokes being Improved Cylinder and Improved Modified. They were equipt with shell extractors instead of shell ejectors. This being very handy when collecting empties. Most came with double triggers, but some with single triggers.
If any repairs are needed, you should have a competent gunsmith do these since some parts may need to be machined.
My information on serial number dating came from " William S. Brophy's book on Marlin Firearm" which I must say was very informative on many brand name firearms. There are also many web sites such as oldguns.net and wikipedia by brand name.
For information on value estimates, try sites like GunsAmerica, AuctionArms,among many others.As I mentioned earlier, some had single triggers. These will generally add up to 50% to the market price of this gun. For general parts, you might try Midway or Numrich Arms.
I am glad to have shared some knowledge on this subject, however, there is much more to be learned from different gun forums, such as handling, balance, shot improvement, etc. Enjoy shooting this fine shotgun of the past. Charles Gage