The Pentax KX is a mechanical shutter body with what appears to be a fairly accurate meter based on this test roll. The only off frame is one where the right side is dark – I’m guessing a dragging shutter at 1/1000sec. The odd thing is that a third of the roll was taken at that speed with no issues.

Pentax KX
SMC Pentax-M 50mm f/2
Kodak Gold 100