Promo
guess you'll have to get a cast of the chamber, slug the bore & work out the twist rate of the barrel, being the date that it is it may be Nitro proofed, but most probably only to Nitro For Black levels.
Lancaster will probably give us an update on this one soon enough!
You have a wonderful piece there mate, certainly intriguing for sure!
It's in marvellous condition to say the least, hope you get her going again.