OK, I'll get it started. When I first started getting back into this in 2001 I ordered a set of decals for a 73-74 CR250M from Vintage Iron (
http://www.vintageiron.com). They were pricey ($39.99) but had every decal I needed. I received them and discovered they had this thick plasitc coating on them. Also the Honda Wing was yellow, not the gold color it should be. Totally unacceptable for an authentic reproduction.
I never used them. What a waste of money. I guess they could be used for a racer if you really didn't care all that much for authenticity. Oh, and I would imagine if you tried to clear coat over these decals you would run into all kinds of problems. They make fair toolbox stickers, which is what I ended up using them for. Pretty expensive toolbox stickers!
I'd rate these decals as a 2 out of 10.
You can see these crappy decals here:
http://www.vintageiron.com/graphics.cfm