Duke,
I'm curious how the footwell was attached in the earlier boats. I was looking back at my build manual and noticed that the various diagrams are dated over a span of several years. Page 116 & 117 is an illustration of the removable cockpit sole and slats, such as would have been installed in later models. These pages are dated 03/76. Various pages such as 113, 114, 118, 123, etc., show illustrations of the cockpit well without the cutout for the removable floor. I see no details of how the well and/or floor were attached at all. Would you mind uploading some photos, now that you have your teak off?
I should think that it would be fairly simple to glass in the well (assuming it is fastened another way now) and then build a removable floor such as those installed in later boats. There isn't anything all the complex about the design. I'm about to reinforce my own in the next few weeks. The lip over which the hatch is placed varies considerably in width and strength. I'm not sure how it might ever have sealed properly. If it's helpful, I can upload photos of the current configuration, as well as the modifications. Let me know.
Jack