I come to this sport as a converted dartmoor Letterboxer of old so I am surprised how few personal stamps are used to log in at caches.
It was all the rage to cut your own stamp from a rubber to use when visiting the boxes. The Captain Goretex is one in question, made by photocopying a design then ironing it onto a rubber then cutting the design using a lino cutter.
There were some real experts a few years back, before the advent of the desktop publisher.
if you do have one post a copy here so we can try to encourage some support, they are more interesting than the usual thanks a lot entry.