I think these microfilms should be in the National archives. If so, it should be easy to compare them.
I am an Australian, I have no idea what you might keep/find in the 'National archives' - and where would 'they' be found?
There was a big controversy a few years back about libraries "deacessioning" (getting rid of) the big bound copies of the original papers that used to be such an important part of their collection, in favor of microfilm. Novelist and crank Nicholson Baker wrote articles and a book about the practice and saved many of the bound library volumes from the incinerator or landfill.
Keeping the original bound copies would make later forgeries harder, but articles like this one jump the gun. If someone is going to go to the trouble to write and make public an article like this, why not take the extra step of at least finding other copies of the microfilm -- if not the original paper -- before wasting everyone's time on wild speculation?