Old Colt's are awesome, And the value can be astronomical, or not so much. Check out various auction sites for colt revolver's and you can probably get a ballpark figure comparing it to the pictures and descriptions
http://www.collectorsfirearms.com/admin/
show_inventory.php?catID=13&subcatID=157
http://www.taylorsfirearms.com/products/cfOpenTop.tpl
http://www.coltsmfg.com/upload/pdfs/Archive%20Services%
20Price%20List%202009.pdf