Thank you Quadraman, that gives me some peace of mind with my decision to go through with the deal!
Here are some pictures of it!
First the unit after I cleaned it up. It didn't need much, just a good wipe down with some light detergent. (yes, the backslash under the delete key is on sideways here):
I pulled off every key and wiped them down real good, then took a q-tip and went through and cleaned out/dusted off the keyboard assembly.
This is the worst of the damage, the scuffing at the edge in front of the keyboard. I had to adjust the photo in photoshop to get the lighting right to show it, the pictures were taken with the phone camera.
And here is the damage to the case badge. Not horrible, but it is noticeable when looking at it:
I'm assuming this is pretty typical, of a neglected //e, to have this much dust and dirt inside the unit:
I gave the logic board a bath of water with a toothbrush scrub and rinse with 91% IPA, it cleaned up real good!
This I/O card is the one that prevents the //e from booting. When installed, it just hangs, displaying "Apple //e" and goes no further. What sucks, is this is the card I need, to use my external 5.25" drive (from what I have researched). The 3.5" Disk Drive Controller Card does not affect it's operation though, but I don't have a 3.5" drive!
The Apple IC with the white sticker on it has tarnished or heat damaged pins. I cleaned them up but it didn't change anything. I might be on the hunt for a new card soon if changing the socket for that IC doesn't fix it.
And the //e booted and connected to a display for the first time in a long time!
So, any ideas on the I/O card issue?