I did. I did a mini tear down just to get some clean pictures and start down the path of learning more about this device.
Pictures to follow. The main board looks to be programmable via FPGA. When I have a NGPC plugged in using the wideboy like adapter cartridge the FPGA error light goes out but other then that the NGPC does nothing to register it's connected. The board will supply power to the handheld - this is a retail NGPC - the unit didn't come with a head unit - not sure if one ever existed. The DC power to the NGP/C had a pot resistor so you can simulate different battery signals. It's inidcated on the pot 12 7 1 and when I turn the dial lower it set off various warnings for low battery on the handheld (so far I think this is intentional for testing)
Tried various console configurations with the serial to usb adapter to the 25 pin RS232 - on unit boot I get a single garbage character on 9600 8N1 but no other baud or config shows anything. (will do more experimenting here)
I tore the unit down and the top board you see in the ebay picture handles power to the secondary terminal below - there are 4 IDE-like connections going to the terminal box. Rom 1 upper, Rom 1 lower, Rob 2 upper, Rob 2 lower. The terminal box only has a reset button. There is a 2 wire connector from the top board to the terminal apart from the IDE -rom connectors. The other side has 25 pin RS232 and also a parallel port.
The terminal below the top board is EMUSE branded model MTV200 (google yielded nothing useful on this + model number)
Below the model number there is some Japanese which translated to Amata Co. LTD - which I have not found overly useful (yet)
Opening the bottom terminal box I found a PCB branded TESCO with what looks like a model number of XROMU 1-1 with rom chips labeled EMUSE v2.1 (even) EMUSE v2.1 (odd)
I will upload photos tomorrow but figured I would share what I learned so far.
** UPDATE ** Found a manual on internet archive here https://ia802901.us.archive.org/11/items/neopop_source/Emulation.PDF