How much of this is original

[Grant Bowker]

I agree that it is C60X. Only about 2700 made (one source gives 2710).
The brake booster is not original (but the vacuum reserve tank inside the left frame rail is original).
Many small brackets on the frame match C60X.
The 5 blade fan and rear engine mounts resemble the 270 in the C60X. The deep oil pan is consistent with later production (early 7-5/16" deep, late 11-7/8" deep, neither is listed as CMP unique). I don't know enough to say with total certainty that the engine is or is not C60X.
Dual rear wheels are not normal C60X in Canadian usage, but could have been swapped on.