Two piece sets have become commonplace with OA issues for national events (NOAC and Jamboree). They typically include a lodge flap and a lower chevron that continues the flap design. Some lodges get pretty clever with their designs, you can do a search on eBay and turn up a variety of examples. Tamegonit Lodge/Tribe of Mic-O-Say/Heart of America council have jointly produced two sets for recent National Jamborees (2001 and 2005). In the case of the 2001 set, a fake of the lower chevron has surfaced. Pictured below are the two patches. The one on the left is the original, while the one on the right is the fake.
The easiest way to tell the difference is by looking at the Mic-O-Say claws on the left hand side of the patch. The original patch has black claws, while the fake has silver-mylar claws.
The fakes show up on eBay fairly regularly, keep an eye out. There are no apparent differences between the companion OA flap and the flap commonly sold with the fake chevron.
Broad Kaw Valley 