Beginner here, with new to me Parker DH

[Cal Genereux]

I'm wondering where I can find some instruction on properly cleaning up my new gun. I've owned many guns but not a collector like this. It is in "as found" condition. I want to clean it up but not do anything that would detract from the value. It isn't even in my possession yet, I expect it will be later next week. I just want to have some knowledge on what to do and not and gather any needed supplies. If someone can point me to a section of the forum or an FAQ or article it would be greatly appreciated. Thank you in advance.