Proofhouse.com has Colt sn data.
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.
@1969
Proofhouse.com has Colt serial number tables.
1970
1959
1929
and the model is..................................
You did not list the serial number. The serial number should follow this example - CCB8765
1971
1919-1922
made about 1958
Manufactured in 1950