Well I never, havent seen a reversed hand NePlus Ultra lock (or even knew they existed) but the few standard ones I had varied fractionally on dimensions and the dp IIRC. Difficult one that as even if someone has a reversed lock to measure there may still be small differences, depends just how tiny a hole you were planning I suppose Alan.
Found most powderproof locks of that era Milner’s, Chubbs etc showed small variations in positions and dp’s. I will never forget a GP normal NePlus I opened 30 years ago and wow, that had one of the toughest hardplates of anything I ever encountered and yes, everything was very slightly out. It was Xmas eve and I was there till midnight. Most weren’t anywhere near that hard though so hope that ones a softie as it might be a bit of an unknown…