As far as the Addendum goes, he is referring to the Power Transformer. The letter that came with the kit explains a bit about the current Power Transformers that are available. You have to make an artificial center tap, which is shown in one of the attached images. The newer PT’s went away with the center tap on the filament line, so you will need to connect two of the 100Ω resistors from those green leads to ground.
I don’t think that is the problem though. The other image shows the red and yellow leads should be wired to the pins of the Rectifier. It doesn’t show where but the red goes to 6 & 4 and the yellow to 8 and 2.
Black will connect to the switch and fuse.
If those are different colors than you have on the PT, let us know!