If the gun appears unfired or factory fired only and does include the factory colt box and paperwork, it would typically be worth somewhere between $4500-$5000 in mint condition. I have a consecutive numbered set of Boa's myself (one 4" and one 6") that are pristine and only factory fired and they are only going to continue to increase in value.
If your colt is the thunderer model (you do not say) then it was made in 1902.
100-1000+ depending on exactly what it is.
value depends on overall condition.................
value depends on overall condition, model ..................
Colt revolver44-40serial6423103
100-1000 depending on specifics
100-1000 USD
value depends on overall condition...........
what model, caliber. ????????
10-1000 USD depending on specifics.
300-500
Impossible to value with just the sn and no other description.