Sorry, missed this.
If you still have the original hardware, some general advice:
- photograph or scan every PCB, good enough to read all the component numbers and printing. If you cannot, jot it all down by hand. An exact motherboard model name and number *may* be good enough.
- dump ANY firmware: motherboard BIOS, video card BIOS, and any other ROMs
- get a list of every component inside the PC, period. Exact manufacturers and model numbers.
- instead of just copying the game files, image the hard drive (if it is still pristine and untouched by you), if via a USB adapter ideally with a write-blocker like "thumbscrew" to prevent whatever host OS you interface it with from writing back to it (Windows 7+ is known to do this for certain). Make a note of the CHS settings in the BIOS and get the exact make and model number of the drive. Linux "dd" can work to make an image. Or WinHex (registered) on Windows. These days we also want to get the ATA ID string when we can.
- also, make a note of the CMOS settings.
The security dongle, if it contains a ROM, will need to be dumped. At the very least, an attempt to disassemble it. Hopefully it is not filled with epoxy.
The button input board might also have a ROM on it or a microcontroller that has internal ROM which will need to be dumped. Unlikely based on your description but we'd need to see.
Some tutorials:
https://wiki.mamedev.org/index.php/How_to_correctly_document_a_PCBhttps://wiki.mamedev.org/index.php/Dumping_romshttps://wiki.mamedev.org/index.php/Taking_pictures_and_other_mediasFor more in-depth advice you will want to contact The Dumping Union. The best way is via Smitdogg at MAMEWorld:
http://www.mameworld.info/ubbthreads/showprofile.php?Cat=&User=2