It is a single metal container (evap unit?) with the hose outlets at the bottom. You can remove the back of the seat (a few screws) and remove it totally from the seat and then replace the seat back if you like.
You can see it poking out the bottom here:
and here:
Here is the unit by its...
It should be from a 1970, could be a 1965... Do you just want the upper part (switch arm/collar only) or the bottom part as well (the actual switch / plug(s))?
Shawn