A late reply, "The Rolleiflex SL66/SLX Way" by Mannheim says all lenses with Bay VI front filter mountings can be retro mounted. The maximum magnification is less with the 80/4 Distagon retro mounted than the 80/2.8 Planar.

It really makes no sense to retro mount the 150/4 or 250/5.6 lenses. Normally you retro mount either of the two 80's or the 50. The 40mm Distagon is not Bay VI.