When I asked about it a few years ago Bruce told me he thought he made about fifty of the pre-extrusion type windshield frames. I sent him a copy of the article I wrote for the newsletter a while back and asked him to look it over. I haven't heard anything back but hopefully he'll be able to add to or clarify things. From what I've seen of survival rates, 20% is a pretty consistent average, but the problem with the first-generation floorpan Manxes is that they aren't labeled as such in the Registry so there may be even more already registered that we don't know of, so its very difficult to estimate how many are out there.  Both Jason and Mike's first-gen floorpan Manxes have been in the Registry for a while but I only heard about them when they posted in this thread.

Also, I believe there were approximately 1400 Manxes made before they started putting number tags on them. The very first tag which was put on a Manx at the Newport Beach factory in Feb 68 was number 1401. I believe the reason they started with that number is because it was the actual correct number. I wrote about it in the Number Tag article