I've been looking at the symbols on the keys and there's plenty I'm just not familiar with.
PF7, PF12 and PF21 all have the same "double arrow" symbol on the front, which seems....redundant.
For the keys on the left side, the bottom left corner key has "little square <--> upright rectangle" on top and "wide rectangle with a line thru it with a loop to the right" on the front.
I don't know what meanings these symbols hold and in what context (word processing, programming, CAD,

) and why they would merit a dedicated key.
Thanks all for the input so far, any suggestions or further ideas are appreciated.
Edit: While I'm not quite ready to take it apart, I am more than willing to take any pictures of anything if I missed a detail that might help figuring out what this is.