I would run a compression test to see if it's just valves, but probably time for rings and valve job. Why? They are all over the place, not consistent patterns, color, etc.
I might be comparing apples to oranges, but this is what I have on my drag car.
This is ONLY to winch the car into the trailer, NOT to secure it inside the trailer.
http://i1285.photobucket.com/albums/a585/CenTx2012RT/IMG_3657_zps4d1d30a9.jpg