if the LDS film has 'parish of ..' at the top of each page then it is of the 1911 official copy - most likely as they filmed virtually everything in the Rolls Office in late 1940's. (actually fairly obviously a copy, as in same modern hand whereas the actual regs vary from very neat to very poor hands according to curate/vicar/clerk)

I believe that the FHS worked from the actual parish registers (in one or two cases probably from a later copy for the early sections) - I know that in at least in a couple of cases they had to take a portable copier along to the vestry as the Vicar would not allow the books out of his sight. The books were copied and then transcribed by a few people - the late Noreen Cottier did much of the proof reading and arranged for publication, including allowing microfilming by LDS.