Problems with breathers and ventilation usually lead to blue smoke because oil is forced where it shouldn't be. White smoke is water. If it is coolant you should be able to smell a sweet smell in the exhaust.

I wouldn't have the compression test done--I would do it myself. The testing tool is relatively cheap--off-brand ones on e-bay are under 20 bucks--and the test is just a matter of pulling the spark plugs one at a time. You will want to do that anyway just to see what they look like. If you plan to hang around old cars and compression test kit is definitely worth the investment.