All engines consume
oil between servicing, fact of life.
If yours has no external leaks, it has to be burning it.
500 miles at say 10MPG is 50 gallons of fuel.
1 quart mixed with 50 gallons would go unnoticed out the exhaust.
The
oil gets consumed through the inlet guide, the exhaust guide if the exhaust system works too good, and past the ring pack.
The
oil is also suspended in the crankcase air and consumed via the pcv system.
I would have a look at the hose between the PCV valve and the carburettor.
Maybe you need to incorporate an air/oil separator tank.