The name of P. Webley was still used for several years after the merger of the companies on certain ranges of gun (as was the name of W&C Scott).

Here's a link to a list of Scott and Webley & Scott serial numbers. Beware though - there were other short serial number ranges that may not be part of the table on the link - I'll check later to see if I've got more information.

http://gunshop.com/dgsnos5.htm

The actual sales records for the rifles were lost or destroyed, only the records for most of the shotguns remain.