This forum’s always been a good sounding board for valuations - the good deals get snapped up fast - lots of haggling and discussing on fairly priced deals - and the overpriced deals get appropriate feedback.
Just my two cents, but a 15 second google of the interwebs certainly provides some corroborating context.
There are no comparable completed sales for Sentinel MK I revolvers on gunbroker because the fixed sight MK I is rare compared to the adjustable sight MK IV. Two Mark IV's have sold for $625-$775 with lots of bids on both. The higher priced one was satin nickel though. You have to add value for that.
Given condition, added rarity, and some real-world current comparable sales I don't think he's out of line.
The contour and lack of checkering.Just curious... what is wrong with the wooden grips?