just got a receiver from Brownells. process took about 2 months. Numrich should be similar except for requirement to register receiver
1. order -Brownells hold it for you
2. get application for international import certificate (IIC) from DFAIT
3, fill out IIC application with order info
4. while you're waiting, download & fill out US end user certificate (DSP 83)
5. while you're waiting, register receiver with CFC- you will need verifier to sign - certificate will arrive within a couple of weeks or sooner if you download application to register & mail it attention "new imports section"
6. when you get stamped IIC, mail it along with DSP-83 to Brownells,
7. wait 4 weeks for Brownells to get export certificate- they keep it.
8 when theyship, brownells sends tracking # so you know its on its way. I'm advised custioms may phone you for a fax opf regiostration certificate, PAL, etc. (mine was sent directly to me but I have sent them copies of my PAL other times)
you will not need to register if you are getting parts not a receiver (don't know about DSP 83)
like someone said, call them up, they know their requirements
all of the above is free on the canadian side. but at all takes time there may be paperwork fees from exporter. ship USPS NOT UPS
you can avoid all this by going to Questar who do this as a business & seem to have an excellent reputation & also do complete firearms imports,