if you want to get this done you're going to need to get the mold specs from melissa, have your own set of molds milled at a very good machine shop with a very experienced operator, then send them to SP. unless someone who wants this done is actually that operator, this is going to be prohibitively expensive
HOWEVER! i would be in for a set that used dolch colors and the standard SP legends (maybe a couple of custom legends for modifiers or something) but didn't have all the kerning and centering weirdness of gb3
eta: actually it occurs to me that there may be CNC laser cutters that could make the molds.