1. the strange pins in the plates could be starter pins.
2. the fence is as simple as it gets - clamp in place and route - designed more for edge work on 1/2" or 3/4" material, but also very useful for dado and rebates.
3. the piece with the raised rail is a "spacer fence" that Bob and Rick from the 'The Router Workshop' use for box making - as yours has holes in each corner, it is a 3/8" spacer fence.
4. During Summer my plate was tight to fit - acting on advice from the forum, I just sanded a little bit of each corner to get a good fit.
Do the plates you have, have any holes or grooves in them?
I don't mind if other members disagree with my comments.
I don't profess to know everything, and I may learn something new.
"Never attribute to malice that which is adequately explained by stupidity."