Your best bet is to contact TNW directly and see what they can do. Or perhaps contact North Sylva now that they are the Canadian TNW distributor
I purchased the parts to rebuild some TNW bolts many years ago directly from TNW, and had to pay an export fee.
The weak link with the TNW MG34 is the Semi Auto Sear... Such a small part, and can wear out, sooner or later. Plus, it's $140USD!
For any TNW MG34 owner in Canada, I recommend buying the TNW bolt tune up kits... Sears, rollers, clips, springs, extractors, ejector pins, etc...
Perhaps check with IRunGuns to see if they can import parts if TNW is unwilling?
Good Luck!