There may just be an interesting story there. I can think of four other plastic kits on the market that have coils of rope molded integrally with their decks: the Revell Santa Maria, Flying Cloud, U.S.C.G.C. Eagle, and H.M.S. Victory. (There may be others, but those are the ones my senile memory can call up. The Santa Maria, as I remember, featured a stack of "cargo" as well. For the record - a few kits under other manufacturers' labels, Lindberg and UPC, were "pirated" from the Revell ones and also had the rope coils. But I think Revell was the only company that originated them.)
As demonstrations of the state of the model manufacturer's art, they were actually rather impressive; you could see the individual strands of the rope. I agree, though, that in this day and age such things are inappropriate in a serious scale model.
Now here's the interesting thing. In the fifties and the early sixties Revell was issuing sailing ship kits in what olde tymers like me came to think of as its "three-dollar series" fairly steadily. They were about 18" long, and their scales were chosen to make them fit in standard-sized boxes. According to Dr. Graham's fine book on the history of Revell, the sequence in which they were originally released was as follows: U.S.S. Constitution (1956), H.M.S. Bounty (1956), Santa Maria (1957), Flying Cloud (1957), U.S.C.G.C. Eagle (1958), H.M.S. Victory (1959), Golden Hind (1965), Mayflower (1966), and Charles W. Morgan (1968). (I'm leaving out some spurious kits that were modified reissues of the others: the "Beagle," "Stag Hound," and "Seeadler.")
Note that the integrally-molded rope coils appeared in four kits that were issued in sequence, between 1957 and 1959. That seems to suggest that the masters for those four kits were sculpted by the same individual - and that somebody in Revell's management during the late fifties thought rope coils were nice. Then the idea got dropped, to reappear suddenly (and briefly) in the early nineties. (At least I guess that's when it happened. Dr. Graham stops his coverage in 1979, so the book doesn't mention the Nina or Pinta.)
Aircraft modelers know that Revell issued three classic WWI aircraft kits, in 1/28 scale in 1957: the Sopwith Camel, SPAD XIII, and Fokker DR-1. Neither Revell nor anybody else made an airplane kit in that scale for thirty-five years. Then, in the early nineties, the Revell 1/28 Fokker D-VII suddenly appeared on the scene. Reviewers at the time (FSM's review archive on the web doesn't go back that far) commented that the kit looked like it had been designed back in the fifties, along with the other three, and kept in cold storage for several decades.
I wonder if we're looking at something similar in the case of the Nina and Pinta - i.e., that those kits were designed by the same artisans who designed the Santa Maria kit fifty years ago and, for some reason, not released until the early nineties (right at the time when the Fokker D-VII appeared).
The big argument against that is that the parts breakdown of the Revell Nina, as shown in Vagabond Astronomer's photos, is remarkably similar to that of the Heller kit. (We've established that they aren't the same kit. But what are the chances of two minds coming up independently with that approach to the bulwarks?)
On the other hand, the Revell Nina seems to have that characteristic, T-shaped stand - which, so far as I know, no other manufacturer's kits had.
Incredibly insignicant trivia in the grand scheme of the universe, but interesting nonetheless.