Hi Mike:
I had a chance to take a closer look at the headblock area schematics of the A807 Mk I and II. It turns out both versions use the same Repro preamp (1.727.430), and it would have two sets of (beige shielded) cables going to the audio board. However, the Repro preamp is connected to the repro head by what it looks like to be a ribbon connector (to be confirmed when I look under the actual headblock) at the preamp circuit board and terminated into a female DB25 subminiature connector to be mated with the head wiring.
As far as I know, the A807 repro head has about 200mH of inductance and would work directly with a seduction tape preamp although controlling hum and other noise will be a challenge. Again, I have not tried the direct wiring of an A807 first hand yet. But I did help a friend wire out a head with 200mH inducance and used the Seduction as a preamp to adjust tape head azimuth and played some tapes with good results.
Ki