Have now spent far too much time analysing specimens of the new pound coins, and have established the following varieties:
There are, so far, 10 obverses, 6 edge types and 15 reverse types. So far the combinations of these obverses, edges and reverses is as follows:
Obv 1 Edge 1 Rev A Obv 2 Edge 2 Rev B Obv 3 Edge 3 Rev C Obv 4 Edge 4 Rev D Obv 5 Edge 4 Rev E Obv 6 Edge 3 Rev F
Obv 6 Edge 3 Rev G Obv 6 Edge 5 Rev H Obv 5 Edge 5 Rev A Obv 6 Edge 3 Rev H Obv 7 Edge 5 Rev J Obv 8 Edge 3 Rev K
Obv 9 Edge 6 Rev L Obv 9 Edge 3 Rev M Obv 9 Edge 3 Rev N Obv 8 Edge 2 Rev O Obv 9 Edge 3 Rev G Obv 10 Edge 5 Rev G
Obv 9 Edge 5 Rev C Obv 4 Edge 2 Rev H Obv 8 Edge 2 Rev B Obv 4 Edge 2 Rev A Obv 7 Edge 2 Rev B
The key obverse indicators are the position of the truncation, the position of the top of the diadem and the gap between the 'T' and the inner ring. For the reverse, the indicators are the right hand leaf of the thistle, the part of the rose centre which is cut by the inner ring, the position of the 'D' relative to the inner ring and the position of the small DP, again in relation to the inner ring. As far as the edges go, the type is indicated by whether the milling below the shield is to the left or right and where it actually starts from. I also have one specimen where the JC on the obverse is 'squashed' into the truncation, instead of being separated from it. Not sure how that happened.
In addition, two specimens have a missing lower leg of the 'P' in 'DP'. All this from a relatively small sample of 2016 coins, which tends to suggest that the Mint's standards have slipped.
It may well be that each of the types I have analysed has other indicators that further differentiate them. To be honest my brain hurts (and my eyes) with all this checking and cross checking. If anyone is interetsed, or is doing any research themselves, I'm happy to provide details of the indicators for each type I have found.