I don't know what is adorable or not, that might be your area of expertise, however, if a government agents expertise and advise is being brought into question, I am positive they will defend their qualifications and work and by doing so, also defend and testify for me!
Lets keep this hypothetical in mind here. I am going to add some specifics just so we aren't arguing circles over nothing. Feel free to play along, or change the facts to suit YOUR imagined scenario. I am game.
Lets say you have a handgun, and a letter from the CFP saying your handgun is an antique. You get pulled over in a routine traffic stop, and the cop asks if you have a firearm in the car. You say yes, but its an antique. He says let me see. You comply. He finds your antique handgun in the trunk, in a locked box, but no trigger lock. Because he agrees with my interpretation of the law, he lays a charge for violating 86(2) of the criminal code, failure to transport in accordance with the regs.
You lawyer up, and give your lawyer your letter, which at face value appears to be duly issued by the CFP offering the legal opinion that this firearm is an antique under Canadian law. At a pretrial meeting your lawyer shares your letter with the crown argueing it proves that the firearm is not restricted and therefore no offence has been committed. The crown offers to drop all charges if you simply forfeit the firearm. Your lawyer thinks this is a great offer, but you refuse.
At this point the crown needs to prepare for trial, and in order to go to trial has to determine if the elements of the offence are made. I'll spare you the full list, but included in that list is determining the classification of the firearm in question in order to know WHICH section of the regulations for storage are applicable. The firearm gets sent off to the lab for analysis, to answer the specific questions.
Is this a firearm per S2 of the criminal code.
If yes, is this a handgun per S84(1) of the criminal code.
If yes, what is the length of the barrel?
If longer than 105mm then it is a restricted firearm and the regulations for transportation of restricted firearms apply.
It will not be in question that you didn't follow the regulations for restricted firearms.
You will argue as a defense that its an antique not a restricted. The judge will ask you to show him the section of law that specifies where an antique firearm is either exempt from the definition of handgun, or restricted firearm, in S84(1) of the code. I invite you to do so.
Failing that, the judge will ask you to show anywhere in law where those Section 84(1) definitions of handgun and restricted firearms do not apply to S 86(2) of the code, or regulations made under 117(H) of the code for that purpose, or that an antique firearm is deemed not to be a restricted firearm for the purposes of 86(2) of the code, or alternatively from the regulations in question. I invite you do so.
Failing that, the judge will ask you to show anywhere in law where the definition antique is created as a mutually exclusively category from restricted firearm. I invite you to do so.
Failing that, the judge will you ask you to show him anything in law that creates ambiguity over any of the above, such that in the absence of clear law supporting your claim, you can at least raise a reasonable doubt. Here you offer your letter. Nothing in that letter will address of any of these issues, as your letter ONLY establishes that your firearm is an antique and is subject to the exemption of "firearm" for the purposes of certain sections, 86(2) not being among them. You call the government employee as a witness, and all they can do is agree with the letter you already have, which did you no good, or they could in fact disagree and undermine the letter, which would render you liable to several additional charges.
Having offered absolutely nothing in law that establishes an antique handgun is NOT a restricted firearm for the purposes of 86(2) of the criminal code, what else is there? What reasonable doubt have you raised that you did not commit the offence of transporting a restricted firearm in contravention to the regulations for restricted firearms.
You see the issue isn't in establishing that your firearm is an antique. The issue is that it is clearly captured under the definition of restricted firearm, and nothing in law says an antique handgun is not restricted, and therefore it subject to the same treatment under S86(2) as every other restricted firearm.