Anything from nothing to thousands of Dollars. There's no way to narrow it down more than that without knowing who the manufacturer is and what model the revolver is.
Winchester did not make a revolver in 32-20.
150.00
10-90 usd
25-75 USD or so
Requires professional appraisal
25-75 USD
10-100 USD or so
Requires hands on appraisal
No such weapon made by S&W
The value of a IV FR Johnsons arms 32 caliber Fitchburg mass revolver is actually dependent upon a number of factors. Most important of these factors would be the condition of the revolver.
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).
Blue Book of Gun Values