Apparently I was wrong, except the part about a self respecting engineer....
Originally Posted by Thomas Wilson
From your picture, it would appear that you have one hell of a nice enlarger, albeit one designed with 5"x7" negatives in mind, not 6x6.
My advice would be to remove the 80mm lens, bend some 12 gauge copper wire in a forked loop that bends out of the way of the light path, slip the forks into the grooves on the aperture ring, and then tape the hell out of it. Then remount the lens.