Pretty nice, light, powerful hunter that's reasonably accurate if the cylinder indexing is adjusted properly . The pellet is blown from the cylinder rather than pushed like a Sumatra so might be pellet fussy. Mine needs the indexing fixed so isn't accurate. I made a hammer stop buffer out of a faucet seal so it can use lighter pellets or take the buffer out to run full power. To check the indexing , pull the trigger as you pull the hammer back all the way and see if the cylinder has any play while still holding the hammer back. Should be minimal. To check cylinder alignment , do the same but push a cleaning rod from the muzzle to feel for misalignment.
I don't know much about the value and have no idea who could work on them.
Bob