You do not have to have a 12(6) to get a 12(6) gun, but your dad may have to pass away first. You may be able to ask the RCMP and see if the transfer can happen when he is alive but I doubt it. As is listed in the below link (I also posted the part about prohibited) you can inherit the prohibited gun but will not get a 12(6) put on your lilcense, there would be a stipulation for you to be able to have only that prohib on your license, not be able to deal them. If you want to sell it I think you would be able to do that to a proper dealer, you would also be able to leave it to a direct relative of yourself.
This rule has been put in place for family heirlooms.
Too bad you cannot get it now, but I don't think that would fly.
http://www.rcmp-grc.gc.ca/cfp-pcaf/fs-fd/will-testament-eng.htm
Prohibited Firearms
•Prohibited firearms can be transferred to an individual who has a Possession and Acquisition Licence (PAL) which includes the appropriate prohibited licence privilege.
•If the deceased individual had prohibited privileges on his or her licence, prohibited firearms in the estate can be transferred to certain family members even if they do not have grandfathered privileges, providing: ◦the prohibited firearm is a grandfathered handgun described in subsection 12(6.1) of the Firearms Act, with a barrel equal to or less than 105 mm in length or designed or adapted to discharge .25 or .32 caliber cartridges; and
â—¦the prohibited handgun was manufactured before 1946; and
â—¦the individual is the spouse, common-law partner, brother, sister, child or grandchild of the deceased registered owner; and
â—¦the handgun is used for a permitted purpose such as target shooting or as part of a collection.