It seems that even Franklin was interested in Leupold's work. Through the wonders of Google Books I came across an interesting little tidbit. In a draft of a letter to an unnamed friend dated March 17th 1775, Franklin wrote:
"Being about to embark for America, this line is just to take leave, wishing you every kind of felicity, and to request, that if you have not yet purchased for me the Theatrum Machinarum, you will now omit doing it, as I have the offer of a set here. But, if you have purchased it, your draft on me will be duly paid in my absence by Mrs. Stevenson, in whose hands I leave my affairs till my return, which I propose, God willing, in October." (notes, pg. 149)
Given the reference to a "set" I assume that Franklin was in search of Leupold's work.
Franklin, Benjamin and Jared Sparks (1840). The works of Benjamin Franklin: Containing several political and historical tracts not included in any former edition, and many letters official and private not hitherto published; with notes and a life of the author. Hilliard, Gray, and Company : Boston.