Beesley designed Body action Lancaster. Self opening action. Yea, pretty unique. The original checkering was more than likely a round top diamond cut at approx 16 to 18 lpi at a 60 or 65 degree angle. This gun like most body actions carries a 0 prefix in the serial number...gun was probably not made at 151 New Bond St. London, but made in Birmingham by a trade maker like Osborne.
Coarse checkering is to my eye attractive too...and way more functional. Other makers thought the same...Dickson for example.
I know a very good stockmaker here in Utah that has probably 30 to 40 blanks that look like or look better than this guns. The blanks are out there.