Charlie
The alum panels were secured by self tapping screws into the original holes. You do have to be very careful with the length of the screws as they can easily mark the glass. I cut the ends off all the screws I used to make them as short as possible.
The seals were originaly a made of a material called "furlex", and I did fit this on my first attempt. It has a steel core which is divided into small segments and you can get the seal to grip the alloy panels.
It didn't work very well for me and after trying all sorts of adhesive to get the things to hold in place, I gave up and used some more modern seal which clipped into place. It looks fine and forms an effective choice. I guess it depends on your choice as to the final use of the car, concours competitions or not.
One of the worst parts (I found)of finishing my Healey was fitting the window winder handles. Fitting the small retaining pin is almost impossible with the alloy panel on. The only way I could do it was to enlist the help of a friend to push the panel in so that I could slide the retaining pin in place. Let me know how you got on with this part of your restoration.
Good Luck