Tony,
That tank was modified for the installation of the Canadian Indestructible Roller Device (CIRD) mine roller.
I have not found any historic paperwork indicating when it became part of the RCAC Museum collection. To the best of my knowledge, the painted markings are not original to the tank.
It does have two engine blocks loosely sitting in the engine compartment and they are in very poor shape. See this link for a couple of images of the engine compartment when we opened it up about a year ago:
https://www.facebook.com/BordenMilitaryMuseum/photos
Colin