Is there any way to tell the date of manufacture on pythons built after 1985 without getting a letter from the factory? All my books stop at 1985. I have a high polish stainless # PN017XX that I am wondering about. I know they didn't start using this finish until after 1985 and I thought someone out there might have a python with a serial number close to this that could give me an idea when mine was built. Thanks