Delta jointer serial number 2-1102

Hello: This is my Delta jointer that I've had for several years now. It was my grandfather's and I believe that it is from the late 1930's or early 40's. It has served me well over the years but now I'm having a problem with it not cutting evenly. It is taking less material off on the fence side when face jointing and it is also tapering the board front to back. More material is being taken off from the leading edge when face jointing. I have reset my knives several times with a jig in conjunction with a dial indicator. I am certain that that is not the issue. I have also checked my tables to make sure they are coplaner. When I run my dial indicator from side to side on the outfeed table, the fence side is .002 high. Would that make a difference in more material being taken off from side to side? Also, does that explain the tapering when face jointing? I'm frustrated because I don't know what else I can do. If it is determined that I have to raise or lower one side of my outfeed table to correct the problems I'm having, I would love some information on how I go about doing that. As you can see in the one photo, there are four screws on the base lower casting on the pulley side. Are those involved at all so that I can shim the outfeed table, assuming that shimming is the solution? I really don't see anything else that is adjustable. I would truly appreciate any help that anyone can give me because without my jointer working properly, I'm kinda at a standstill. Thank you for your help.