I've never seen one, but that doesn't mean anything. I have seen early proof sets busted up into separate slabs and kept together as a set.
PCGS likely no. NGC not sure if they still do it, you may have to be a bulk submission or something I am not sure. ANACS was developing one recently, never looked into whether or not it is out yet.
Oh, right. So some may do the multi holder slabs. The reason I'm asking, I have a 1990 mint set with a struck thru grease cent in it. Just wondering what the significance or advantages would be to keep the set together and have it graded?
Even if one of the TPG's did offer a multi-holder, I don't see why it would be worthwhile to have all of the coins graded. The grease-filled die is not worth grading and attribution. Remember, you would have to pay extra for the error. If the other coins graded higher than MS67, you would be better off having them graded individually. Chris
In general, it's cheaper to buy a coin already slabbed rather than going through the expense of grading.