On balance, rather the action and such being a filthy mess from rain and harsh hunting conditions, this gun to date appears to be one that more than likely has, for the most part, been resting peacefully in its case, which no doubt can still create the need for some attention after enough time has passed. I don't know what time frame under those conditions would warrant a full cleaning, but the fact remains, I'm just speculating on previous usage and have a lot of unknowns about its earlier years. That's probably a good enough reason to get it in the hands of someone that knows his way around the the other side of the sidelocks better than I do.... smile
The gentleman at Purdey said "We prefer to handle internal maintenance in house, which is why you will not find modern references to removing/cleaning the locks." Will hopefully soon have a good "in house" option that's nearer by.