Great info in this thread
good point as you could do a say red box with the font in front of it to simulate your desired coin plate and officeworks run transparencies through their photo developer which gives a stronger, truer colour and sharper image. I recently did this for something pin related that I am working on with excellent results.
Swinks, I can't remember how far we got with them, but I think maybe you still have the samples for the Williams coin inserts? Have you got any further with reproducing them?