Mid 2015 and Late 2015 5k iMac Logic Board Swap

[Techo238]

I have a mid 2015 5K iMac with a dead logic board but a fully working display and was wondering if it’s possible to swap out the board for a late 2015 one. 

From what I’ve read, it’s not possible as the display panels are ever so slightly different between the 2 models (and knowing how apple operates with this kinda thing I can believe it) but I have access to a cheap late 2015 board and can’t find any evidence of anyone trying this, just people saying that the 2 are incompatible. 
 

Also, does anyone know what the differences between the panels actually are, as far as I can tell from images they look pretty much identical.