[MaciekA]

I have the G&P Canadian Carbine. It's definitely not sold as a C7, it is sold as a C8 (and has the markings for a C8). By far the nicest thing about it is the trademark powder coat paint job that G&P does on its receivers. Very very nice. As far as I know G&P isn't making a C7 or planning to.

To accomplish this I'd personally take a different route..

It is possible to find M4s with blank trades (I have one and they're out there). Once you have a blank-trade M4 receiver in your hands, there are people on this forum who can do perfect-looking laser engravings and such to make your trades say whatever you want them to say.

For these sorts of things you will absolutely need to get age-verified to get anywhere with it. You will find people who can point you in the right direction (even if it takes a few oddball out-of-the-way steps) if you post in the AV areas on this site.

The rest of the stuff, Elcan sights, correct-looking stocks, handguards, and Canadian-style mags are extremely easy to find. If you have your heart set on a certain receiver that isn't offered on any retail gun however, it will take some doing.