Most No7 rifles were built from bare receivers which had been scrubbed (presumably) by the CF.
If your receiver is parkerized (and not dated in the 1950s), it is 95% that it was built from spare parts and one of these receivers.
They've been available that way to the public at least since the late '70s.
hundreds of them have been sold within the last 5 years by Ellwood Epps, they came in cardboard CF "Spares" boxes containing 2 scrubbed receivers.
My box is Marked:
Sept.59, 25 central ord. depot, Montreal QC, Sept 59, Part No: 1005.21.103.1133, Nominclature: Body, Quantity: 2
https://www.milsurps.com/content.php...Training-Rifle