Didn't know cabinet decals were avail for Simpsons.
Even when brand new, the factory cabinet decals were very Matt finish.
I always wondered why Stern did the artwork this way.
If u can redecall the machine, decals with a gloss finish or covering from a print shop would be awesome.
Either way, your machine will be great because it sounds like both your dad and yourself will pull out all the stops like you have on all your other pinball machines.