Happy to share this is resolved!
After receiving my PAL recently, I started with my provincial CFO office. Turns out provincial CFOs have nothing to do with classifying firearms, but they gave me a particular extension to dial at the CFP main office. Turns out that extension is no longer valid, but after a few transfers I spoke with someone. Must say, they were very understanding and helpful.
I provided the gun's info (Model, S/N, caliber, barrel length) and my PAL number, CFP looked up the classification in their database; and confirmed the rifle is non-restricted. CFP told me because it is in fact NR I am free to take possession, that there were many classification errors during the registry days. No need to formally re-classify the rifle! CFP told me the records associated with non-restricted models of firearms were destroyed when the long gun registry was abandoned. I.e. the paper copy I have of the registration certificate is the only thing stating the rifle is "restricted".
If anyone else has a similar situation: I'm sorry I don't have the exact extension to share, however; if you call the CFP number (1-800-731-4000) and select option 4 (initiate transfer of a restricted firearm) I'm sure you'll wind up with the right person.
Going shooting this afternoon. Really appreciate the guidance this community gave. Thank you!