Alright. I have read the tutorial and still didn't pick up anything eye-opening. On a whim I decided to paste the modeline for my 640x480 desktop setting into my dkong.ini file; When the game fires up though, the info screen still says it's running at 2560x256. Mame isn't reading my dkong.ini file it would seem. All my dkong.ini file has in it is the modeline info that I'd pasted. Is there more formatting that needs to occur or something?
EDIT: I moved it into ini\source and it worked. I'm at 480 now. Maybe the adjustments I've made to account for overscan at 256 aren't actually doing as much as I thought, which is why nothing appears to happen in dkong.