The Portsmouth Numbers listed in the Weta Wiki page appear to be incorrect.
The Wiki page lists the RYA PN as 950. The latest PDF on the current RYA website says the Weta PN is 960.
The Wiki page says the US PN is 78.5 US Sailing doesn’t appear to HAVE a PN for the Weta. In any case, a RYA rating of 960 slots the Weta directly between the Sonar (940/81.0) and the 470 (973/86.3.) This would make the US number somewhere around 83.5 if it exists. 78.5 would seem to be wildly inaccurate.