Acorn Econet Fileserver

Are there any Econet enthusiasts here? I've just bought most of an Acorn Econet fileserver (it's missing the 2 floppy drioves and their cables, the mainboard and PSU look intact). The mainboard contains : 65C102 CPU 64K EPROM (2 off 27256). I've not tried to look at their contents yet 64K DRAM WD2793 disk controller (not what I'd expect from Acorn) 6522 VIA Real time clcok chip and backup battery TTL glue An Econet module (looks like the one used in a Master or Arc, the type with the hardware collision detection). Oddly theres a 26LS30 on the mainboard, does this thing source the Exonet clock too? The PSU looks to be a normal switch-mode unit giving +5V and +12V On the back are the 5 pin DIN econet socket, a 26 pin header identified as 'Printer' (presumably wired as a BBC micro printer port) and a 34 pin header. I am told this is to add a hard disk, and it looks similar to a Beeb's 1MHz bus. I assume it takes the normal SASI host adapter and ST506 bridgboard (I have spares of those somewhere...) On the front are 2 LEDs (power and mode) and what looks like a reflectiove optoswitch (why?) Can anyone tell me anything more about it, how to use it, what the intenral links do, etc? -tony