Hi Bud,
Can you tell the chassis number ? I am very curious about the transition between S1 and S1a...
Also, in my experience of several years in the South of France with a fixed-windows S1, unless it is very hot, when driving the cockpit stays reasonably fresh, and if you use the fan, even in traffic, it can be ok ; of course, once again, if it's not a particularly hot day.
So in my opinion, it may be worth consideration to keep the windows as they are...This first edition of the S1 is a legacy of Chapman's "crazy" genius, isn't it ?