Off topic.. but check this out!

[soonerbillz]

Picked this up at a auction.
No idea what year it is. It is a compression tester. It records the pressure on little cards using a arm with a piece of tiny crayon attached. The cards have a pressure scale printed on them.. and are removable to show the customer or other. Made by MotoMeter.. which I think also made radiator temperature gauge caps in the teens and 20's

[AAAltered]

Remarkably they still make recording gauges...

https://www.samstagsales.com/motometer.htm

[soonerbillz]

Remarkably they still make recording gauges...

https://www.samstagsales.com/motometer.htm

Well I'll be damned!

[Dvsrd]

 Proper quality kit!  When I did one year of Auto repair class in the early 80s, we had those.
(trade school/ vocational college)

[AAAltered]

I looked around further on that site and see they still have the recording chart paper.  Probably for yours!

[Dvsrd]

https://www.motometer.de/

Proper German engineering. How things should be done 😁