would show not only gas in the oil, but most importantly abnormally high metal content if the engine was damaged.
I use Blackstone Lab for my cars. It is only $17.
For your reference the last Mobil 1 15w50 oil analysis results from 92 600SEL with 117k miles on V12 engine:
Aluminum 3
Chromium 3
Iron 8
Copper 3
Lead 0
Tin 1