For what it's worth, a DjVu of that scan is about 1.4MB. On my phone I can't spot the difference. It's a shame that format never caught on.
[1] http://any2djvu.djvu.org/djvu/170421/82.132.237.218/57676.17...
[1] http://any2djvu.djvu.org/djvu/170421/82.132.237.218/57676.17...
(I included the link in case anyone was interested in the quality and to prove I didn't just make up the number!)