AHHHH! That explains the odd behavior I saw last night!
Turns out that what is stamped out in the back of the chassis for the controls is NOT what they really are, they had stickers to show what they were, but they are long gone, what was marked as CRT bias was really VIDEO PEAKING, which was set in top most setting, and I sort of freaked when I changed it and lost picture and just got a blank raster.
Meaning there may be bad caps or more likely bad resistors, or the switch itself is dirty.
The REAL CRT bias adjustment is indeed a potentiometer, just as the SAMS says, but in a position stamped for something other than CRT bias, and when checked, much to my relief, it was turned 1/3 the way up when it made the video posted yesterday!
