Are the Walther PPK,s marked with a ISP or just normal commercial marking.

That is an old safriland "Clipspringer" holster.. It was an answer to Tex Shoemaker's early paddle holster. I had one for my Model 59 in the late 1980s. I had a Tex Shoemaker for my 2" S&W when I was an Investigator in the Army in the early to mid-70s.

A friend of mine has often told the story about his first ISP issued shotgun in about 1969 being a Winchester model 97 - yep, the one with the exposed hammer - that had pipe wrench marks on the receiver. It was an expansion year for the ISP and equipment was short. I think he felt lucky to have a car with tread on the tires, roll up windows and a heater.....

He said the end of the 97 was when he was holding a suspect at gunpoint and the 97 let go without him touching the trigger. (missed)

Circa 1970, a couple of 97's were posted on the car inventory list in the local trooper office at the jail along with model 12's and Ithaca 37's.

In the early 1970,s while I was a guard at Illinois Menard Penitentery.There were Winchester Model 97 Shotguns in the Armory And the Towers. Their were also Winchester Model 94,s and Thompson submachine guns. Also there were S&W M&P,s and Colt Official Police Revolvers in the Armory

The Walther pistols I saw had no Illinois State Police markings to my recollection. Some of the S&W pistols had inventory numbers on the slide or dust cover of the frame. I think the original model 39’s were stamped Illinois State Police on the right side of the slide under the ejection port.

I think the Walther PPK/PPKs were purchased late enough that if they had any ISP markings it might have been an inventory number. By the time ISP transitioned to Glock they had quit using any inventory number markings or Department name.

I heard Glock offered Agencies the option of adding logo or badge/star markings for no additional cost but ISP declined.