I'm afraid that the printed copies of
Treatises aren't much kop either but I did find pics online, I believe it was googlebooks. I find having the printed text very useful to just flick through. When in doubt, Ackermann's online via the internet archive has pictures in some issues, I think it's the 1810-1812 ones. Unfortunately the Internet Archive has become user unfriendly so it will take more work than it used to. When you do manage to get there you should be able to download each issue as a PDF, and read at your leisure.
Amazon do have some excellent random bits and pieces, I have a book of enigmas[riddles], charades and transpositions with answers, from the Classic Reprint Series, a list of merchant ships at sea for 1812 with their size and owner, and the odd pocket almanack which gives things like the dates of the University terms. It's also well worth the £79 a year to subscribe to the British Newspaper Online source. I use it constantly, checking the weather, and odd news snippets as background to my writing.