Fox Collectors

I have serial #52801. It is marked The Sterlingworth Co. on the sides of the receiver, the barrels also are marked The Sterlingworth Co. with the Philadelphia address. It is a Pin gun. My question is the length of pull to the Fox buttplate measures 13 7/8. The wood measures 13 11/16. The butt surface is flat not curved. Is this a correct length of pull for this gun or has it been shortend ?
Thanks for any comments.

Regards,
James Orr

I would say maybe shortened, most butt plates measure 3/16", Original length 14 1/18" Length of wood 13 15/16" for a small charge the factory would modify the LOP, only way to tell is get a letter.