What have I got here?

[RickB]

I think the slice next to the two controlled by the joystick is a motor valve. Hence the two relief valve cartridge looking appendages next to the actual spool. This provides crossover relief which is what a motor valve does. Not many open center motor valves have flow control built in, but some do, this one doesn't. The "in" port is probably on the end by itself, the other end slice probably contains the 'out' and 'power beyond' ports which can be either isolated from each other or common depending on system requirements and the presence or absence of the proper plug or sleeve. Looking at both photos gives a better view than either by itself.

 

[rdbrumfield]

when you talk of three links under the boot, I think one is a pivot point to stablize the handle so it can be used sideways as well as for and back. Having the extra two by themselves can be very handy for attachments.
I can't be sure of my observations without having it in my hands, but that is my experience with what you have.