I wouldn't know if somebody has done this but, I'd say it probably would have been done to a strictly trailered show car because it would dramatically change the integrity of the chassis... particularly the roof's structure. It was constructed with roll-over accidents in mind as well as some mild [upside-down] falls.
Moreover, a quality T-top (or similar) conversion costs around $1000 if not more. That alone would disappoint one from doing a T-top conversion when they knowingly can do other stuff w/ that $$$.

It's a shame that the NSX, del Sol and the S2000 are the only T-top (or similar) cars under Honda. IMHO, an Integra w/ a T-top (or similar) would be pretty cool (especially in Hawaii where it does get quite warm). Just keep the aforementioned issues in mind... and weigh out your choices yourself, Ok!?