bingofuel
As I explained above, the instructor was in the RH seat and the 'co-pilot' he was checking in the LH seat. If all went well the instructor did a 'crew-change' with another co-pilot who took his place in the RH seat.
My logbook shows we were airborne for 30 minutes, so just a few circuits, maybe a PAR or ILS ( I can't remember, but doubt it! ), no practising any 3 engined stuff, possibly a 4 engined go-around/overshoot.
That would be the last time the co flew in the captain's seat until he returned for a captain's course some 2 and a half years later.