Yes, the loop is for manual transmissions. On automatics it's the Neutral Safety Switch (NSS) path. On automatics the starter will not engage unless the transmission is in Park or Neutral as the starter solenoid current path is through the NSS. On manual transmissions this is not required, so there is a short loop to bypass that function.
Appreciate your help. I'll post a rendering of the tag like I did with the underdash, instrument panel and rear lights for the 67 fastbacks (with light group option).