wrote:
...
3) Believe it or not the camera has provision for behind the lens
filters. Would behind the lens filters perform better than placing them
up front, and consider that these are uncoated lenses?

I doubt that. A filter between the lens and the film becomes a part of
the optical system. It affects focusing.

Many cameras have threads in the rear, but they are for the retainer
ring that keeps the rear element/cell in its place.

-- Lassi