AMEN to that! I also have Scottish ancestry and there's quite a market for clan tartans, crests and emblems. There are a few tartans that are in the public domain; such as, Stewart and Black Watch, so you see a lot of them. There are also tartans that have been altered slightly so that they can be sold publicly.
Personally, I like to wear wool tartan neckties because they tie and hang nicely and add a splash of color to an otherwise drab suit. I like the tartans that have been adopted by the Maritime Provinces. The green & red tartan of New Brunswick and the mostly green tartan of Cape Breton are two of my favorites.