I don't suppose you remember the paint code for the wheels on your Mehari? I've bought a tin of Renault 667 which was described on a French forum as being the paint for pre-1968 wheels. But I'm thinking it might be for the wheels and bumpers on the later cars. The colour of your Mehari wheels looks about right for my early Renault 4.
I haven't brought out the spraygun yet with the 667, so maybe it will be OK. But for a backup plan....