I'll weigh in on the rotocasting converstion because there are a lot of mysteries. Firstly cymbal companies are universally secretive about just what they do to get the results that they are revered for or they think are beneficial.
When rotocasting was initially used ,it was in order to deliver an as impurity free and as complete a blank as possible. This was labour saving ,in the extreme. No longer did the cymbal need to be partially shaped by milling and there would have been an immediate reduction in culls or seconds. As a result of the process, there are telltale signs , the curved flutes on the bell and bow, are supposed to be signs. Another is the relative freedom from pock marks and inclusions on the surface.
A picture was posted of a Paiste 602 , showing multiple curved flutes and I have seen the very same thing on A. Zildjian cymbals. Perhaps , there are multiple reasons for these marks.
I was always led to believe that 602's were sheet spun cymbals , from a specific alloy---made in a similar process as this [ame]http://www.youtube.com/watch?v=DLuoE_xSMsU[/ame]. Many , mostly cheaper cymbals are done in this way. There is always the possibility of hot spinning, which might cause even different marks. It would be easy to leave marks during spinning and lathing, that might mimic rotocasting marks. Both Paiste and A. Zildjian did/do make sheet spun cymbals but maybe they used rotocasting as well.
As the molten metal flows to the perimeter of a rotocast blank, it will be cooling and becoming less liquid. I have seen a number of cymbals that have these telltale waves ,at the edge, that look like the material was still spinning as it solidified. Here is a current VDF link , showing telltale wavy , rimples, at around 2:00 http://www.vintagedrumforum.com/attachment.php?attachmentid=17650&d=1277256311
The Pinkstoerber, quote regarding rotocasting never being used at TOSCO, could have been deliberately misleading. Tosco and UFIP had a close relationship and there is some evidence that they both made custom runs for some of the same companies , over the years. It would have been completely likely that Tosco would have farmed out some rotocasting to UFIP, on their behalf , even if they didn't use the technique in house.