Assuming you have the same style of wheel as I do on my
1962 Overlander, I have found a great solution thanks to another member here. There is not a direct replacement, but if you don't mind spending some $ and replacing all 4 wheel covers, Bob Drake is the man. Take a look at their web site for repop Ford wheel covers that will work.
www.bobdrake.com. The part #s for mine were 01A-1130-BM for the hub caps and I also added beauty rings - 01A-18303-15. A very cool look! Pricey though... My wheels are 15" and have a series of clips around the center that the caps clip on.
Hope this helps!
Steve D