Yes and there were "modifications".
NT's 65-66-67 were 8 feet 7 1/4 inches wide and NT's 68
through to 77 were 9 feet 4 1/4 inches overall width.
NT's 68 to 77 had the hand brake relocated and did not
have the forward pressurising fan.
Incidentally, 65-66-67 only had 700 gallon fuel tanks
as against 920 gallons for the rest.
Big beef from fitters were the Serck Behr hydrostatic
fan drives, they were messy oily shits of things.
BTW, the NT's were the most powerful (power to weight)
narrow gauge engine in their time, they introduced Cab
over Bull Bar "mainline loco cab" design to Australia,
they brought to the rail industry here, charge air
intercooling, which was why the basic Sulzer 6LDA was
able to crank out 1400 HP.
Cheers
----Tell