Easy, create a transparent .png file like this and overlay it on the window sticker and you put it in plain sight where somebody can't remove it or gloss over it.
Maybe even put your website URL on it so others could order them too.
For me, personally, I find any reproduction documentation, trim tags, restamped engine blocks, transmissions, etc. offensive that's trying to be passed off as real with 'aging,' 'seat spring stains,' etc. to appear real.
Not saying you're doing this to help people deceive others but it's no more 'right' than a reproduction birth certificate, high school/college/other diploma, SSN card, etc.
As one poster noted they'd like to have one with what their car has now with no intention of ever trying to pass off a mid 60s car as original with a 454. A (clearly marked) reproduction window sticker with the way the owner's car is now - maybe even with aftermarket equipment - someone might spring for $20-$25 a pop. There will still be people out there that have perceptions of some things and seeing it on paper will 'make it so' in their minds regardless of how wrong it really is.
Just saying the idea may go over well in the Corvette community but I don't think it'd sit well with the Chevelle community and you'd wind up getting a bad rep. and even cause a few good, legit cars to come under scrutiny.