You wont find anything on the RSSB website pal. Send an E-Mail to Portec Rail asking for installation diagrams. I have them somewhere but cannot find them. If you get stuck PM me and i'll try my best and dig them out.
From memory the plunger on the older mechanical lubricators stands up above the rail head by about a 1/4" or perhaps just a tad more. It would be placed just off the field side of the rail head, where the outer edge of the wheel will run over it.