Hi Theo,
Well I guess that e-bay can be good or bad, in all my dozens of transactions I only had 2 bad purchases and had no problem returning the item to the seller.
In my ocaisonal selling only 1 sale, a gut in Norway was not thrilled with the shipping charges so he never paid...
So I think it is what you make of it, once in a while you have a problem.
Now then back to the topic, you realize you need a model C (two types of that one) as well a couple of variations on the S2a...
Oh, if I temember correctly the model D (Delux) was followed by the Z, a slightly less expensive D, these bothe preceeded the S.
Good luck hunting!
joe