The '67/'68 wheel fits OK, but the tin horn ''cup'' is different, the '69/'72 is either deeper or shallower, ICRW.
You can get the right '60-'68 internal horn cup tin from The Truck and Car Shop of Orange [County, Calif.]. They also have the rubber insert for the horn button if yours is torn/deteriorated.
You may need the whole Horn Cap Retainer Kit.
'69 + later used a plastic trapeziodal horn button for the 2-spoke wheel.
www.truckandcarshop.com/6072.html