gunbroker.com
50-200 USD depending on condition
100-250 or so
100-300 USD depending on specifics
38 special.
No
You take it to a gunsmith
.38 Special, yes. Other .38 cartridges (such as the .38 Long Colt or .38 Super), no.
38 special is only a revolver caliber. that's like saying a 44 magnum revolver or a 500 special revolver. a revolver is a revolver
165
100-300
The Mark IV was not made in .32 caliber. It was in caliber .38-200 (the 38 S&W). Value is $200 and up, depending on condition. A SIMILAR revolver is made by IOF in India in caliber .32 S&W Long, and sells new (in India) for about $1,300 USD (no competing companies).