After  having a good look at the hole and removed window, I came up with a plan.
I'd  remove the windows one at a time, make a template from the hole, recaulk the window and put  it back in. I'd use butyl tape for the 'caulk'. After a few trips in the rain,  I'd know whether I needed to buy new windows or whether my re-sealing had gotten  the job done.
On  the first window, I removed the 'felt channel run', which was loops of 'U' shaped stainless wire with only thin random attachments of fabric 
then realized that I'd probably have to remove some rivits and open up the frame to get the new channel run in...bummer -- not something that I wanted to do. I ordered some unbeaded all rubber felt. Maybe I can get it in without removing the window. I'll post the model number if it works. I think I'm just going to reseal the other windows without messing with the felt or cosmetic inserts.
then realized that I'd probably have to remove some rivits and open up the frame to get the new channel run in...bummer -- not something that I wanted to do. I ordered some unbeaded all rubber felt. Maybe I can get it in without removing the window. I'll post the model number if it works. I think I'm just going to reseal the other windows without messing with the felt or cosmetic inserts.
First thing to do, is remove the screws that broke off when the clamping ring was undone. I've got a tiny pair of Vice Grips which I modified by grinding the nose to a V which clears the channel for more rotational movement.
Then after  some heat to the frame/screw
and  some penetrating oil (I use a 50/50 mix of ATF and Acetone) all one needs is some judicious wiggling to get the old broken screw out. 
I  may feel differently about this approach depending on how many I have to do.  Drilling new holes is an option.
Messing with  the window on the bench is impossible - holding it and the glass while trying to  get anything done is awkward. I put the window lightly in the vice.
Next,  after pulling out all the felt, I needed to clean up the channel. A screwdriver  pushing Scotchbrite gets the job done quite nicely.
Before  I ordered the new channel run, I messed with some Velcro to see if I could make  that work. It does work, either the hook or loop, but getting the sticky-back  stuff in place is a monumental task and I didn't want to have to use any glue to keep  straight fabric in place. 
So  now I'm waiting for the felt channel run, and pondering....I don't care if my  windows leak, I just don't want them leaking inside the boat. Hmmmm.



















 
 