If you want quality Wm Powell & Sons guns are a bargain !!!I've owned , sold and repaired a few. Without exception the internal workmanship has been superb. Occasionally you find examples that are a little quirky in as much as you will see gorgeous exhibition wood and only line border engraving, internally they are gems.
Mikes comment about Moor St. Station bought back many memories. Out the doors , under the underpass,right then left into Carrs Lane. The first gun and last gun I ever bought retail(in UK) were from there.If the gun in question is in good original condition mechanically then you won't regret it at $6000 which would be a fair price to both parties