This is an attempt to list all “official” hardware related to the Nascom computers.
If anyone has anything to add, please let me know!

NASCOM-1 The original computer that started it all
NASCOM-2 The second version – much enhanced
NASCOM-3 The first Lucas Logic version – basically a NASCOM-2 in a case with a power supply and small expansion bus. Optional disk drives.
3A & 8A Power supplies +/- 5V and +/-12v power to the people!
Buffer Board Required to connect NASCOM-1 (only) to the Nas-bus as the processor signals were unbuffered.
12-slot Motherboard 77-way edge connectors (Not required for the Nascom 3, which had its own internal motherboard within the case)
RAM Board Available in 0,4k,8k,16k,32k. Also had 4x 2708 EPROM sockets.
RAM (B) Board A later, more flexible and reliable RAM board but without EPROM sockets
I/O Board Various combinations of ICs up to 3xPIO 1xUART 1xCTC.
Floppy Disk Controller What it says really…
The IMP Printer Slightly non-standard dot-matrix printer
Nas-Net Serial port networking system for 1 master machine & up to 32 slaves.
Nascom Test Board For testing nascom systems, presumably…