Hi all!

I was wondering if anyone knows the differences between these enlargers? Or are they all similar (I believe the 22A and 22B are almost the same). I'm asking, because I just came across an online manual (pdf) for the Bogen Salon Special, but I have a Bogen 22B, and it appears to me that there is very little difference between my 22B and the SS. Also I just won a 120 negative carrier for a 22A, and figured it would fit my 22B based on the description. Any info would be appreciated.