Revolvers are not intended to be disassembled by the user for regular maintenance and cleaning. Would strongly recommend you find a qualified pistolsmith if you need work done. Spray gun cleaner can clean internal lockwork without taking it apart.
about 1973
100-500 USD
Colt data at Proofhouse.com
1958
No serial number provided.
Around 1973.
Between 1971 & 1972
-5-500 USD or so
Can't be answered without the serial number.
Impossible to answer without the serial number.
It will be marked on the weapon.
your colt trooper mkIII was made in 1978.