Thank you Bookbox for your comments. The images on Ancestry, after a little change to brightness and contrast, can be made much more readable, so I'm able with a little help here and there to make good progress in transcribing this document. I'm actually using a piece of software called Transcipt written by Jacob Boerema and once the image is tidied up and straightened, the software works well and is a very good aid to transcribing the documents I'm working on.
As far as this will is concerned, so far there is only one reason for wanting to consult the original (if it exists, and if we ever escape from this current little issue of Covid-19) is that there is a gap on one line where a percentage interest rate should be shown. However, this is not of vital concern, although I've still just under half of the remainder to do.
When it is all done comes the next interesting challenge, and that is to try and work out what it all means! The primary intent is clearly to provide income for his wife, and legacies for his children in terms of income for his daughters and land and property for his sons. However, there are references to another will under which Joseph is a legatee (which I can't find), and his pecuniary liabilities at the death of other residents of Chatteris.