I'm intrigued to know where those truck maps came from then!
If they were supplied from TomTom via download, then they will be "locked" to the device they were intended for, to prevent piracy, so no "swaps" to another unit are possible.
TT used to also supply maps on SD card, and those were locked to the serial number of the SD card itself, so they could be used in any device (so long as the software was compatible with them).
If they are pirated maps, I'm afraid this forum can't advise further...