"...looking to expand my collection to prohib. status..." Was this not covered in your PAL/RPAL course?
The only way you can is by inheriting one.
"Exception: If you are not grandfathered, the only prohibited firearms you may possess or acquire are handguns with a barrel length of 105 mm or less or that discharge .25 or .32 calibre ammunition, and only if all of the following criteria are met:
- the handgun was made before 1946, and
- the handgun was registered in Canada on December 1, 1998, and you are the child, grandchild, brother, sister or spouse of the lawful owner,
- and you are acquiring it for an approved purpose such as target shooting or as part of a collection.
In these circumstances, you can lawfully possess the handgun in question, but you are not grandfathered or authorized to acquire more prohibited handguns."