Just came upon this post. I just received the twin to this rifle from England and it has the same proof issues. Marked as Nitro on top of barrels but no nitro proofs on the flats. I'd be lying if I said it didn't bother me a little but I have to agree that Rigby would never have made a 450 black or NFB rifle that heavy. Mine is 11 Lbs 6 Oz. Doing some checking on this in England as we speak but won't know anything for sure until Monday. The Ledgers only state 450 Bore no additional info on caliber.

Sinner, I respect your opinion and know you do a lot of trading in the market but I spent a lot of time looking for my Rigby with a lot of knowledgeable people helping me and I think the chances of finding a tight sidelock Rigby with good bores for under $40,000 is a real long shot. Too many people overpaying just because they can and more people getting interested in them is really driving prices up.

My 2 cents: Have the bores and other important parts checked out by a reputable smith, offer 40 and walk out with a smile on your face because it won't be long before it is worth a lot more.

Josh