Good maker, not quite in the top tier, but well thought of. I have a friend who has a Hussey sidelock and it's quite a nice gun.
Concerns: Are chambers still 2-1/2 inches? In a gun that lightweight, if they've been lengthened, the barrel walls are going to be pretty thin just forward of the chambers and way, way too close to your face or the arm that's holding the barrels. Minimum wall thickness of 0.020 is really at the edge on a 12 gauge, probably less than desirable on a 20 gauge. Location of that measurement is important. My preference, and that of most guys I know who buy British sxs, is nothing less than 0.025 at 9 inches from the breech face. Walls that thin are subject to denting if they hit almost anything, like a tree trunk when swinging on a grouse or a stone when putting the gun down to deal with a dog or a downed bird. Top lever looks to be a little bit to the left of center, but that might be camera angle. You'll also want to confirm the gun is tight on its face, removing the forend to check for any movement of the barrels with the forend off.
In any event, if he decides to buy it, I'd limit my use of it to RST or other similar 2-1/2 inch lower pressure loads.
