Hello Enfieldspares, like your name as I am a trials rider here in the USA and ride vinatge machinary although usually it is Japanese and only '70's or '80's vintage. I also ride a modern Beta but am better on the vinatge stuff. On to your question: I am not sure. I am not a scope technology expert and never have actually thought about how the zeroing works...I just do it! Plus, my first time shooting this single shot was all new to me, just finding that the windage and elevation are all in the top turret was a surprise. When I get a chance I will dig it out of the safe (it has been about 5 degrees fahrenheit here in the morings and the guns are away till Alril most likely) and turn it a few bits to see if I can tell, although I prefer not to get it too far out of whack as it took me a few extra rounds to get it figured out and set to where it is. 
9 fingers
PS - back to bikes: I did ride a fantastic AJS trials conversion done by a gentleman about 5 hours south of me. It was amazing but I had to be careful not to drop it on the rocks we were riding so I was a little tentative.

Hi Enfieldspares, sorry this took so long but finally made it to the safe and found the gun in question. Looking through the scope it appears as if the post reticle is shifted off to the left so I guess that answers your question. Mine has very bad ring marks and signs of someone trying to cover them but the optics are excellent and I paid $65 USD so well worth it in the end. Good luck to you.
9 fingers