No but I just saw a pair fitted to a TVR Vixen and they are nice. I don't see any problem with them fitting into a NA other than the steep recline might not give you all the seat travel you want. They remind me of Porsche 914 seats.
I keep coming back to these GTS Classic seats time and time again. They just look so cool and are less expensive than the Nakamae seats. My favorite models is the Targa Florio in corduroy center / vinyl sides with red piping. I'm still working on my custom race seat project but I'd really love to have a pair of these for street driving and for show.