Forest_Service_74

I just bought a 74 w100 ex-forest service truck and I noticed a couple things on the inner fenders and the hood cowl. On the inner fenders you can see it was marked ad says ON M 72 5. It says that on both inner fenders. Other thing I saw was this tag on the hood cowl, just 4 digits 8097. I tried to research them but I must be searching them wrong or there isn't much information on them. Hoping someone here will be able to shed some light on what they may mean.

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