I wonder what was the conclusion of the conversion envisioned in the article. Having once acquired a 4 seater hardtop for my ex-wife's BN7 with the vision of "converting" it to fit a two-seater, I think it might be more accurate to state that whatever points of
similarity between the 2 and 4 seater hardtops
end at what would be the B pillar. Amongst other things you cannot stretch plexiglass to accommodate the need for a deeper back window and rebuilding the bottom rail is way more easily said than done.
After a lot of measuring and acquiring knowledge from those that had been there I finally abandoned the project, sold the 2 + 2 top and ultimately located a proper top from a BN6 that had been stored in someone's rafters for a number of years. Even with a seemingly good candidate, fitting that top to give acceptable air gaps along the shroud was a challenging job and i am of the belief that, as with fenders and other body panels, there is enough variation from car to car and hardtop to hardtop to pretty much guarantee that a lot of fitting will be necessary.
The NICAL top on my 100 is, of course, an entirely aftermarket deal and fitting that was another story indeed....