Nice.
Looks like it needs a bit of a clean up.
You will have to use that light meter though because in-camera TTL (through the lens) metering only came about in the 1960s.
Those Helios lenses are meant to be quite good. I believe Horney has one.
With a camera that old, the light seals about the film compartment may have decayed, in which case you'll get light leakage and ruined film. But you'll probably only know that once you've put a film through.
I was looking at buying a fully manual film SLR recently, I might still do it for fun.
Have fun with your Zenit.
