You are commenting on an older table saw by Frame Square. In most table saws there are "tilt adjustment" features for the squaring of the blade to the table. In the case of this specialized table saw this adjustment might not be visible from outside the base cabinet. I do not see any mention in the manual for the model# 1000 in the reference section of this forum.
My thought that there is wear on the spindle and that you might be able to place an ultra thin shim behind the bracket to adjust the angle to the bed of the saw that holds the spindle to the frame of the machine is the actual spindle is in specification. OR the sliding table, including the sliding mechanism, might be bent that is causing this inaccuracy of the angle.