Pretty sure that these use a new, purpose made receiver. They also fire from the closed bolt. They have passed BATFE inspection, so are seriously semi-auto. The only reason that the receiver could fail RCMP inspection would be if it uses rewelded parts of an original receiver.
I suppose that the procedure would be to 1) purchase one; 2) register it in Canada; 3) apply for a Cdn. import permit; 4) send the Cdn. import permit to the licenced US exporter, so they could apply for an export permit; 5) arrange for a carrier for transportation; 6) pay taxes. A Cdn. importing service could be used, to simplify the procedure. This pre-supposes that the RCMP would issue a certificate, and that US authorities would issue an export permit. Perhaps it would be worth a call to the RCMP. The techs are no doubt aware of this firearm, perhaps there is already a ruling on its acceptability.