75-150 USD
You need a good gunsmith
No known published sn data.
About $150
10-450 usd
You must call Colt to find out.
100-300 USD or so
The USA. It is a .38spl that is lengthened slightly to make it a magnum.
Nothing. Have it checked by a gunsmith to be sure.
Do not attempt to do this. You may cause damage or injury.
About $150-250, depending on condition, blued or stainless, etc.
To be certain, check with Rossi Customer Service.Phone: (305) 474-0401
there are dedicated web sites for colt and Winchester manufacturing dates etc. Google it