The designer on the 2/18 and 3/18 is listed as C Pyle/O Minney. The difference between the two appears to be the rig; the 2/18 carries 271 sq and the 3/18 carries 250 sq. Listed weights are 450 and 435 respectively. As of 1990 the 2/18 listed at $9382, $3000 more than a NACRA 5.8. I can see why they are hard to find. I also remember an article from the 1970s covering a distance race in PR with a fleet of H16s and P cats, so there must have been some on the east coast.