Hi Gus,
for as far as I know is the rest of the hardware the same between the different models. The difference between the old and the new is that it has the recessed connectors, and the front panel is the flat hardened glass.
The hardware differences know to me are
1) The FPGA: Altera Cyclone IV versus Anlogic AL3-10
2) The touch panel. There are differences in the number of sensors used. Most of them have, out the top of my head, 16x10, but I also have one that has 20x14.
3) The display. They have used at least three types, one of which has quite a displacement causing the screen to shift up and to the left.
The firmware is, for as far as I know, the same functionality wise. (Apart from ye or ne writing the touch panel configuration)
Can you post a photo of your pcb? And also some photo's of the device in action.
If you are willing to play with it, you could make a jtag connection on to the FPGA and see if it is possible to reprogram. The older board has it routed to an unpopulated header, so a bit easier.
As you can read in the last 4 or 5 pages, we are in the process of making a new FPGA programming. It is for the Anlogic device, but the verilog can be adapted for the Altera device.
It is a fun little device and would be unfortunate if, after all your efforts it is binned.
Regards,
Peter