Been 40 years since I flew Barons, admittedly before the era of LOP. But none those numbers are reflected in my memory.
I seem to recall 24 gph (110 lph) @ 180 KTAS was what we used. Admittedly we ran the engines well rich of peak as LOP was unheard of then.
26.5 lph per engine at 180 KTAS is certainly impressive that’s almost half of what we used to plan on. That LOP regime sure is amazing.
Nevertheless, arriving in Bulolo in the morning with only 30 mins of fuel is sporting. That implies having only 13 litres of fuel remaining in each tank!