Good stuff so far Geo. Ignore the colours in the drawing - they're just representative.
The hose was made of a fabric-covered rubber, coloured a sort of sage green, and connected to the pipe aft of the seat frame. The clips, as Andy pointed out, where for stowage of the hose when not in use - it would be 'hanging' free, attached to a similar, shorter, green rubber hose from the mask. But, once assembled, all that will be visible is the forward section of the hose, so detail hidden by the seat and fuselage frame will not be seen anyway.