'81 380 SEL camshafts

I've decided to replace my camshafts and rockers myself. My mechanic checked the oil when he heard a knock and found only a quart left. I had him do diagnostics and sure enough, the cam tips are scored. Not pretty. The compression was fine which leads me to believe that the rings were fine.

The last oil change was in December (I'm horrible!) so I'm averaging my oil loss at a little more than a quart a month. If this consumption is average for the age, the rings are fine, and there are no oil leaks, what else could cause the loss?

I'm afraid that I need to do a valve job as well. If I don't need to pull off the cylinder head, I'm comfortable doing the cam work myslef. The engine has 190k miles on it and the camshafts were replaced at 140k.

Anything else I should look at while I'm getting dirty? Any do's or do not's?

Thanks!

- Matt