No one goes through that much effort to forge a complete pipe. You'd know it for sure if someone did. I've seen misidentification of pipes people sell on eBay such as a Kaywoodie but it's really a Dr. Grabow or one that's so called never smoked, or getting the year of manufacture wrong.
The forgeries come when you have an already established manufacturing and supply chain and use that to make copies and claim the original. Like purses and handbags. Making even a pipe-like object takes a bit of tooling and know how not easily found anymore to make it look real enough. You'd be able to tell.
I've seen a lot of forgeries in militaria collectibles. But that again is because there already is a manufacturing setup to make these items and to make a copy isn't to hard after that.