That's an XT clone all right 😀
What I can tell about the cards:
- the first card (closest to the drives) is an I/O + floppy controller.
- second card has a "104866" part number. That implies a Xebec 1210C MFM HDD controller.
- third card is a memory card. Can't make out chips on it or on motherboard, I'd guess 512kB on the one and 128kB on the other, but could be wrong there.
- fourth is the display card. Can't make out what it is, as it's not a 1:1 clone of one of the original IBM (or Hercules) cards, but the lack of large chips means it's almost certainly not EGA and probably not Hercules either. That leaves either CGA or MDA, and given it was used in a business setting, I'd guess it's MDA.
By the way, you can boot the system, just not get display output. If you hear it beep and count down RAM, it's probable (almost) 100%, and worth looking for a TTL monitor or (better) an MCE2VGA adapter. If some tantalum caps blow up in your face, it's not quite 100%, but you know where to start 😉