the person who had it used a reduction back from
an eastman #4 on it to save $$ and make smaller portraits.
the carraige back allowed to slide the ground glass/film
and put 2 images on 1 sheet of film
there should be an insert that blocks off some of the light ..
it has a rectangular cut out and a 2-sided rectangualr
box projecting back to the lens the size of the image you wanted on the
of the reduction back. if no insert, it is just a smaller film back ( think rollfilm back on a 4x5 )
it looks like you have a couple of packard shutters
and probably one inside the camera that opens and closes with the hose/bulb sticking out of the lens board
it probably still works. ...
(
http://web.archive.org/web/20020207030445/http://www.hubphoto.com/photography-products.htm )
hub photo is still around, but i don't know if they are involved with packard shutters anymore, nothing on their new website about it ...
your vitax is a barrel lens it doesn''t have a shutter of its own.
sorry to read of its blade problems.
from what i remember its aperture blades were made out of some sort of weird early 1900s celluloid
and dissolves in water and might be difficult to find/make for repair
have fun making photographs with that nice camera and "stuff"
john