Larger piece has engraved name - yes the manufacturer, but ?also the contributor of the illustration
by jules moderator
I don't think Leitz was the illustrator here. In fact there is a very difficult to read name in the illustration to the right of the base of the instrument. You will need to view the page on the BHL site and increase the magnification to have any chance of seeing it. I noticed that several other images from this article were "signed" in a similar way but so far I have only managed to read one of them - but not this one!