Not clear what is what but I'll give it my best shot. I assume the piece in the top pic is what you call the valve assembly and the bottom pic the filter. Cannot tell what ports are connected for what function. If the gasket mounts on the 'valve assy' (top pic) then it is probably the wrong gasket. In the pic it looks like the old gasket is still stuck to it. On the bottom pic it doesn't look like there are grooves for the gasket to sit in. As for what position the handle should be in for each function you may have to trace out the paths of flow.
Al