Mine has a top speed of 1/400.. I'm pretty sure that makes it a Supermatic 1
Dan I've just taken the cells from the 101mm Ektar and put them in my Epsilon which came with the 203mm Ektar it's size 0 - the shutter's marked Kodak Epsilon, then I tried them in the Copal 0 of my 150mm f5.6 Xenar just to be 100% sure, all identical threads.
The 203mm f7.7 Ektar is a surprisingly small lens because of it's aperture. I was surprised to see the 101mm Ektar in a Zeiss Ikon Compur Rapid for sale on MWClassic's website which is why I tried it for myself.
It may be that some lenses they were going to sell in the UK/Europe were in compatible shutters.
I guess I will have to borrow a Copal 0 and try it for myself..
The 101mm f4.5 Ektar is more common in the Flash Spermatic as you say. My Kodak Referance Handbook shows the 101mm f4.5 Ektar needing a 35mm 1.25" mounting hole and the 127mm f4.5 Etart a 38mm 1.5" hole - so different shutter sizes.
Thanks for trying Dan,much appreciated
Wasn't the 203mm Ektar sold in the UK in the mount size marked "320" which was a standard one? Not so for US models.