sounds like u need to get a better guage. You can even take it to a shop and get them to do it for reaonably cheap.

In anycase compresion is compresion. Miles dont really much to an engine. at 76K, the care you gave that engine from the very first day is what matters. (frequency of oil changes, quality of oil), also driving habbits (like how much u red line, Is it driven in the city mostly, Does it ilde alot?).

I suggest u get it checked by a shop, then worry about the #'s afterwards.