Good guns are where you find them, period.
It does not matter one iota if you get one at Griffin & Howe or a pawn shop. 
I bought a Grant side lever with Boss barrels. All confirmed with Atkins and Boss records. One owner who had the Boss Barrels put on . Wall thickness was in high 20's. Came with a Rhino hide oak and leather case. A Woodward that had new Birmingham barrels , , not sleeved . A Purdey SBT , one of the 59 made. .... all at Cabelas for prices that were atleast 1/2 or less than I would from one of the other sellers . It was easy to negotiate the prices . I always check to see what is in the Library.