The High Standard Sentinel mark IV is a 9 shot blue or nickel plated revolver with wooden grips that was made by High Standard Inc.
It came in a 2 and 4 inch barrel length.
This revolver in good condition may be worth from 175 to 275 US dollars.
If has the magnum cylinder it will.
A quick search on google will surprise you.
about 250 dollars
50-100 USD
50-200 USD
10-500 usd
100-300
The 22 Magnum WMP model R107A can sell online for around $180. This will vary depending on the item condition.
75-275 USD
50-150 or so
100-500 USD or so
50-125 or so