While the Dolphin Pro 1 has a wider nut on the 4-string, I can't imagine Warwick making a special neck blank for the SN. I think the SNs all had the same exact neck blank, dropped into the same pocket on a different body shape. Heck, even the electronics are identical, in the identical spots.
However, this is just what I think makes sense, I have no evidence.
It's good hearing from him even with this bass. Does he still lives in Santo Domingo? I visited Dominican Republic last year, but couldn't rech him
Dunno if this has been put to bed but I can confirm the Lolphin SN TCS BBQ BYOB RSVP ect. etc. has a standard nut width. Same as pretty much all the other wicks, NOT the same as the Pro 1 and Buzzard which are wider nuts.