EHLO 222Lab_Test222,
Is the fourth image where they're getting pulled from? Is this part of an industrial imaging setup? I saw Wacom so I assume imaging/digitizing. If you know what the boards were used for that may help in finding more info, Wacom is going to poison searches since this is a motherboard.
Since you checked the battery, it's possible it won't post because of the input power, this is an AT-era board, so despite being a few pins short the power connector is pitched for AT-P8 and AT-P9. I've worked at enough integrators to know that making it look proprietary is almost as good. Triple check your voltages, if it's AT it's expecting -12V and actually needs it, it's also going to want more 5V compared to 12V.
Since video has been no dice, it's always possible it's only outputting serial, look for RS232.
But that assumes you care about the board, you said you're interested in data recovery and that can be done without a working board; since this is a 486 PC Motherboard you're interested in the three EEPROM chips with printed labels on them as others pointed out.
The "MSDOS" pair will be the OS and may contain software, "CGROM" is going to be the character set for the graphics driver (that appears to be unique given all the Wacom in there). Certainly good potential archival material for sure. Not the only way to do it but you can hack together a Rom dumper out of a Pi Pico if you're inclined
https://github.com/gfoot/picoprom, same is true for an Arduino
Actual data though? That would likely have been spat out to a hard drive not pictured (SCSI?).
All of that to say, there's a sanity check I do professionally (but rarely personally):
What is the replacement cost / potential value and is that worth more than the amount of time I'm going to invest.
If there's limited value in gaining knowledge there: You've got a 486 with a tiny bit of gold and a pile of hard to find spares that are hard to find out how to test

221 Bye,
fifty