Well, I was wrong about Thunder Slot producing a McLeagle. It looks like the wing included in the kit is meant for another livery.
From Giovanni Montiglio, posted on the ItaliaSlot board:
"MessaggioInviato: Mer 26 Set 2018 20:59 Oggetto: Rispondi citando
Hi Rielog,
nice job indeed. It is a matter of fact we will do this version (Penske/Donahue) sometime in the near future as well as the Andretti version with the high rear wing (not Sunoco though)
Regards
Giovanni"