Go to proofhouse.com and take your pick.
1954.
and the model is..................................
.22 cal
Around 1955.
if your pistol is of the model 1911 with serial number 189558 then it was made in 1917 by colt. If it is the revolver then the serial number is to high for the 1917 revolver.
It's a 1954.Thanks!
You can either call Colt or look it up at Proofhouse.com
1972
1957
Proofhouse.com has Colt sn data.
You must call Colt to find out.
Colt Model 1877 "Lightning" Double Action Revolver in caliber .38 Colt and the similar revolver model "Thunderer" in caliber .41 Colt.