Those are models are the first designed and built by John Marlin before the famous model 39 .22 cal repeating rifle. It should be worth quite a lot if in good or even moderate condition. I would definitely check with LeRoy Merz antiqute guns for a quote. These are top notch and fair antique gun dealers... www.merzantique.com
The model 1873 Colt Army .45 revolver was about $17.00.
1873 was the date of the first one.
1873
EMF Company produced the Model 1873 Dakota Single Action Revolver. This link says they no longer make it: http://www.emf-company.com/1873-model-single-action-revolver-dakota2.htm
An 1873 penny is worth about 12 dollars in good conditions.
Colt revolver44-40serial6423103
1873 colt single action army revolver
Why is 1873 worth less than 1874 in the same condition?
The Colt .45 was issued to the army after trials in 1873 and manufactured by the Colts manufacturing Company.
As of the tail end of 2010, you can expect a standard, unaltered (not converted to .45 acp) 1873 Chamelot Delvigne in decent condition to run for anywhere between $600 and $1000. If you're fortunate to have one of the 30,000 1874 Chamelot Delvignes (Officer's model), you can almost double that estimate.
This will need a hands-on appraisal by someone knowledgeable in antique firearms- and it will depend on exact make, model, and condition- none of which you gave us. By the way, the 44-40 cartridge was not developed until 1873.
50- 5000 USD depending on the engraver, engraving, materials used, etc..