I got this Document (see in 226.308 kbyte) with the help of John Tooby and by the friendly people of the Lindley Library at London. Please notice that the copyright is with the Lindley Library.
The Camellia is in table 139, sketched by G.D. Ehret and put to a copper plate by A.L.Wirsing in the year 1786. The Ehret sketch can be seen on the top right of (1740 EHR). Titelface is in Latin and German. The Index says : 139 Camellia I, Tsabekki frutex flore roseo, fructu pyriformi tricocco.
By the way, Ehret published together with Trew the illustrated work:
Plantae selectae with several editions between 1749 and 1771, but there seems to be no Camellia picture up to 1786.