Old D-4 cat oil check

Ok so a friend calls me and asked how do you check the oil on my D-4 cat. Well I have not looked at it so could not tell him for sure. This one if it makes a difference has the pony start.
Thanks

Most Cats you check the oil with the engine running.

Is this by any chance a 7J series tractor ? I do know as per the military technical manual TM5-3126 that tractors 4G-4G9999 and 7J1-5104 and up are to be checked when the engine is not running. Tractors after 7J5104 and I quote "have guards to protect the gauge from spray, so the oil level should be checked with the engine running.

It says with the tractors before 7J5104, which have those obsolete and apparently not needed oil coolers, the oil will drain back down in a few minutes and should be checked within 2 minutes after the engine was shut off. Old information from WWII era books.

I assume that 2T and up tractors should be checked with the engine running. I don't have any books on 6U or 7U tractors, or later, so I am not all that sure what may have changed. My D7 you check while running, but you can obviously pull the dipstick to make sure the crankcase has enough oil to start, then check per the operators instructions while running for correct level. One of the few odd things to know about these.

It reminds me of the Kohler K161T on my tiller, you unscrew the dipstick and check the oil by dipping the stick until the pipe plug touches, but you don't screw it back in and check, that too is in the book, funny how these things differ from the norm isn't it ?

Well, you go me to go look at mine,D4 serial # 7U33676, with pony start. Pulled the stick and turned it over to see the full mark and right their it said " check with the engine running". No marks on the pony dip stick other than the full mark. Guess I have been doing it wrong !! O BTW this has the oil cooler along side the radiator..
Jo