The original mainboard of my Packard Bell Pack-mate 486 computer suffered from broken traces due to a battery leak. Original replacement parts are hard to find and other LPX-type mainboards sometimes have a different distance between the ISA riser and the rear face of the case. I replaced it with a similar LPX mainboard from Compaq.
This 3d model replaces the original metal ISA back-plate which can be removed by drilling out the rivets. Other LPX mainboards likely require other modifications, you can use the Fusion360 Archive files included.
New ISA back-place can be fixed using 3mm metal inserts melted into the print with soldering iron. Or use any other 3mm nut and bolt.
Note that the original metal ISA back-plate also attaches one end of the metal brace that supports the top of the case. This model does not have the attachment point, so the metal brace can not be reinstalled. It's probably not a good idea to place big/heavy monitors on top of the case, but smaller monitors or flatscreens should be no problem.
The author marked this model as their own original creation.