Check out
Classic Parts of America. They offer all the original brochures for the '67-72 Chevy/GMC trucks. As far as the shot of your truck on a t-shirt, any local advertising firm should be able to do that for you for under $20. We checked on having some shirts made for an event and when we contacted our local business they told us we could probably do it cheaper ourselves by doing the iron on type.
Beautiful '69 CST by the way... I recently acquire a '69 CST 2wd SWB truck and could be happier.
Post some pics of your truck if you don't mind.
