civilian or commercial model if a commercial model then the 'C' comes before the serial number Between 1912 & 1950 the Ccame before the serial numbers. Between 1950 & 1970 the C came after. "Commercial"
Serial number
If you mean the 1911 government model, it was made in 1912
Service Model
Identifies the model series.
No such serial number for the Colt detective special, please resubmit.If you mean 700200, than 1957 would be the year. If you mean 700020, it would be the same, 1957.
MT=Match Target
Law Enforcement
If you mean the standard Caliber of a 1911 model colt pistol,then this was chambered in the caliber .45ACP.
Nothing.
mk is short for 'mark'
Proofhouse.com has Colt sn data.
If you mean the Colt lightning Model 1877 double action revolver with serial number 26270 ,it was made in the year 1880 If you mean the lightning .22 rf rifle,it was made in 1897.