After downloading one ply file that is 94mb and then 7zipped it, the size became 11mb. Saving it as a blend makes it 30 mb and 11mb 7zipped. Smithsonians should have made a script that zipped all these files instead of raw download.
Holy smokes!!! I tried obj full res download it worked a treat, fully uv unwrapped and everything. First person to make an old antiques shop render with a nice old workdesk and loads of odd relics, covered in dust and spider webs and a nice old window with light coming through or candles… heh.