57 of these locomotives had Wannentender (one probably of a large type). 15 had Steifrahmentender, and 2 with poss. 2'2'T26 tender (witch soon was placed on the rotary snow plows #6 & #7).
NSB gradually started to modify these locomotives and named them type 63a. The modifications included mounting of smoke deflectors, Norwegian safety valves on the kettle, air suction valves, Norwegian turbine generator on top of the kettle, lowered air pressure pump, elevated marking lights in the front, main headlight on the smokebox door, cinders slide from the smoke box, ladder to the sand box on right side and 2 steps on the left side, modified the sandbox, only sand pipes to the wheels for helping forward drive during slippery start conditions, removing boxes covering the water feeding pipes, extended cabin roof on the sides, roof hatch, garding bars on front windows, handrails on the tenders, extra water filling hatch etc,
These locomotives was in Norwegian service from 1943 - and the last until 1970!!!