Just an update to this...

Since the PC is difficult to remove from the machinery, I don't want to mess with it more than necessary. I took Mark's advice and bought a proper 16GB PATA SSD as it should last longer.

Macrium Reflect was able to write to the PATA SSD without a problem. The old socket 7 motherboard BIOS autodetected the drive right away and we're back up and running.

Thanks.