Here's a link to a zip file file with the manual and copy of the schematic from my Dropbox.
I coloured the supply lines to make it easier to follow.
https://www.dropbox.com/s/y76b60depenvbk8/FT7.zip?dl=0
The link will expire on the 31 May 2019, but if anybody else wants it after then, pm me and I will email it to you (approx 7.5Mb file).
The permanent 12v will be the collector and the 0.7v line (if opposite the 12v one) will be the base. Other two are emitter.