Okay so I have a 1984, 1.5 civic crx. The damn thing is burning oil and don't know why!

I replaced most all gaskets...
Replaced the pcv...
It has great compression numbers on all cylinders (so I am assuming the rings are doing alright)...
The carb has been rebuilt...a few times. . .
New valves, seals, springs, cam...
New oil sump. . .
Etc, etc, etc.

I think I've wasted more time and money than any benefit I'm getting...which is 40-45 mpg...which is good

Anyhoo...any help or suggestions would be great...thanks!