Powermatic Model 50 (green) Gibs?

Hello all, I am trying to rehab a powermatic model 50 6" jointer of the green variety. It used to belong to a shop class, so its had some use. my problem was I could never get the tables to line up. For lack of a better term, they drooped. I could never get them to be coplanar. From what I have heard, the Gibs might be dimpled? I poked around and while cleaning, I see something interesting. 3-4 strips of coke cans are stuck in the dovetails around the Gibs. Some more poking and I decide to take the tables off. Good news, I can get one side off, bad news the other has a stripped set screw, so its staying.

I removed the gibs and cleaned them off. They seem to have some sort of notch cut in them? Attachment 207506
Is this normal If so, should I just put them back and try to just adjust it better? It seems these are hard to find out in the wild. Should be noted, one of the gibs has a small... divot? in the back, looks like maybe it was put in backwards then had the set screw over tightened. I figure I can sand that out.


Thanks in advance,
Stu