I wonder if not shipping an prescribed antique outside of Canada is an actual Canadapost policy, or perhaps a misinformed opinion of a Canadapost employee.
I could"t find anything on the Canadapost site regarding shipping prescribed antiques.
I did find this interesting item:
U.S. Customs regulations require the IRS Employer Identification Number (EIN) or, if an individual, the Social Security Number (SSN), of the U.S. recipient for certain packages being shipped into the U.S. U.S. Customs regulations apply to import shipments with a declared value for customs of U.S. $2,000* or more, for shipments containing plastics, toys, games, or sporting equipment valued at U.S. $250* or more, and for the following commodities valued at U.S. $5* or more: textile or textile products, clothing, leather or leather products, footwear and headwear, all FDA regulated commodities, or other goods that are restricted or controlled requiring a formal entry by the U.S. Customs service. Shipments which are so restricted or controlled or contain commodities that require a B13A Declaration may NOT be shipped by PriorityTM Worldwide service.
All packages scheduled for delivery which do not have the EIN number will be detained until that information can be obtained.
*This limit is subject to change.
Here is where they state the will not ship firearms, and it looks like knives as well, outside Canada:
The following items are not acceptable for carriage to any international destinations unless otherwise indicated by us (Additional restrictions may apply depending on destination. Various regulatory clearances in addition to customs clearance may be required for certain commodities and may extend the transit time):
• Foodstuffs and beverages (perishable or non-perishable).
• Live insects, animals, birds, reptiles and plants, including cut flowers.
• Dead animals or animals that have been mounted.
• Live fish/seafood.
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• APO/FPO addresses, with exceptions. Call Canada Post at 1-888-550-6333.
• COD shipments.
• Human corpses, human organs or body parts, cremated or disinterred human remains.
• Drugs, prescriptions, except to certain countries. Also see item

below.
• Explosives.
• Firearms, weaponry and parts thereof.
• Money (including coins, cash, currency or paper money). We do not accept shipments of cash under any circumstances. If a shipment of cash is sent, we will deposit the cash in a bank account subject to the following terms: (i) if the cash shipped is under $100, a cheque for the cash shipped less an administration fee of 25% of the cash shipped will be mailed to the shipper; and (ii) if the cash shipped is over $100, a cheque for the cash shipped less an administration fee of $35 will be mailed to the shipper.
• Collectable coins and stamps.
• Negotiable stocks, bonds, bank drafts, cash letters, and other negotiable instruments equivalent to cash.
• Gambling devices.
• Lottery tickets.
• Liquor and alcoholic beverages except between licensed distributors (advance arrangements are required).
• Tobacco, in certain countries only.
• Cannabis or marijuana, including cannabis or marijuana intended for recreational or medicinal use, cannabis seeds, plants, resin or any of their derivatives, and synthetic cannabinoids.
• ####ography.
• Furs and fur clothing.
• Hazardous waste, including, but not limited to, used hypodermic needles or syringes, or other medical waste.
• Personal effects where the importer is claiming duty-free entry.
• Shipments moving under a carnet (allows temporary import for display, etc. without duties).
• Drawback claims (request for refund of import duties at time of export).
• Shipments requiring Temporary Importation Bonds (T.I.B.s — allows temporary import for repairs, etc.).
• Wet or dry ice.
• Any shipment which, in our judgment, could cause damage to, or delay of, equipment, personnel or other shipments.
• Any shipment which may require us to obtain a license or permit for its transportation, importation or exportation.
• Any item whose carriage is prohibited by any applicable international treaty, law, government regulation, order or requirement of the country of origin or destination, or of any country through which the shipment may transit.
• Shipments that are wet, leaking or emit a foul odour.
• Fragile Articles/Orientation. We assume no liability for shipments of fragile articles (including, but not limited to, electronic and electrical devices and scientific testing equipment). We do not provide special handling for packaging bearing “Fragile”, “Refrigeration required” or orientation markings. See “Liabilities Not Assumed”.
• Perishables.
k) Cosmetics of any type are unacceptable for shipment to many countries. Call Canada Post at 1-888-550-6333 for further information.
Terms and Conditions PriorityTM Worldwide
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Terms and Conditions PriorityTM Worldwide
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l)
m)
Non-prescription drugs, vitamins, dietary supplements and herbal remedies are unacceptable for shipment to many countries. Because laws and regulations regarding admissibility and clearance procedures vary by destination country, we will assume no responsibility for delivery delays. In the event the shipment does not clear proper regulatory agencies, it will be deemed undeliverable (See “Undeliverable Packages”). If there is any question regarding the admissibility of non-prescription drug shipments, vitamins, dietary supplements and herbal remedies, we suggest that the sender contact the recipient to determine entry requirements. Consult the International Destination Listing available at canadapost.ca/internationallistings for further information.
Shipments with a declared value for customs in excess of that permitted for a specific destination are not acceptable for carriage. The declared value for carriage cannot exceed the declared value for customs as indicated on the PriorityTM Worldwide Air Waybill.
Regards,
Powder man