Don’t remember who, but I had a guy from EBay make some decals for me a few years ago. Had some blank generic center caps on the wheels, found a pic on the web and sent it to him. $30ish bucks.
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/163900845399 Some new Mustang ones. Still would have to get the Maverick decals , but they should be the same since 73 Mustangs came with a similar wheel.
Send a email to Craig Selvey I think he may have what you’re looking for. http://www.maverickcorral.com/
Here it is ...………….. http://mmb.maverick.to/threads/maverick-wheel-center-decals.118681/#post-1137731