Sounds like a great device to have, for any high performance engine building shop, or anyone who does a lot of high performance tuning, for others.
Hey, you could charge guys, to check their compression, just like they charge for dyno time.
It would help in choosing a cam, for an engine of unknown specs.
There is also another neat little device, which I saw used by the tech guys at a dirt track. It is a small scope, on the end of a flexible shaft(sometimes called a flexible borescope). You feed it in thru a spark plug hole. You can look up at the valves & combustion chamber, or down, at the top of the piston. At the dirt track, they were using them to look for illegal oversize valves, and illegal pistons.
One of these could be used to ID the pistons in a Pontiac engine. Might also help get a real ruff idea of deck height--not sure about that ?
https://www.google.com/webhp?sourcei...e%20borescopes