It seems unlikely to me. That number was assigned between April 1 and July 10 of 1914, and I think Wolf was still working for other pipe manufacturers at that time. I gather the stamping on your pipe is faint and difficult to read. Does the OP (or anyone else reading this) have a Wolf Bros pipe with a legible design registration number on it?
If it’s definitely 638866 I can start the wheels turning to order copies of what survived but would prefer a little more certainty first.