Jim, the rough areas I saw are inside the head where the quill rides in, the rough area is the actual machine marks. I believe that the quill(which was machined pretty smooth) was riding on the high areas of the rough machining inside the head casting, so the quill fit nice when new, then the high spots wore down and the quill became loose. It wasn't ridiculous but the slop was noticeable when the quill was extended some. So if you never had the quill out then you would have never seen it, unless you meant your x-ray vision.
My press is much newer, a 2011, so maybe delta started getting sloppy, and your's is fine. My usage is probably like your's, not used much, but used every time I'm in the shop. I was recently using one of those adjustable circle hole cutters, maybe those are a no no for drill presses even though it says drill press use only on it.
Glenn,
I added both bolts, the upper bolt is threaded into the head. It's the one I use to take up the play and will only need adjusted to compensate for wear. The lower bolt is in a through hole and the lever is for a quill lock. This is optional as there is a small lever that acts as a quill lock from the factory, I decided to go this route since I cut the head and the factory quill lock would have acted to spread the head open when in the locked position. My new lock squeezes the head around the quill locking it, so less likely to damage something, plus I like the larger lever much better than the tiny factory one. I basically copied how steel city does theirs.
http://www.steelcitytoolworks.com/products_closeup.cfm?category=4&tool=20520
You can see the similarity there. Anyway, it works and I can't get my head around why all drill presses don't come this way, if you look at most vintage drill presses they have split head castings, I can't see any real difference in manufacturing costs except for the 2 bolts and lever. I suppose they don't don't build them like they used to, actually, I know they don't build them like they used to. I have several old machines ranging from the 1960s to pre WWII tools, they are definitely more solid than most modern machines. However I do have a sawstop pro 3hp cabinet saw and I am very happy with it, its very solid and really well built.
PS, Glenn I joined this forum specifically to ask you about your drill problems in 2009 when I went though the same problem with the delta 17-950 and am very glad I joined. There is a lot of good info on here and people are willing to help you out. I though I would post this fix to give back some of what I learned. After googling "drill press quill slop" I realize I am not the only one with this problem. I have only found one other person that has split their drill press head to fix the problem, most other fixes are with tapping holes in the head and screwing brass screws in to push on the quill to remove the play. I like my method better.