16" Mopar rims - OD of center?

Can anyone tell me the OD of the "centers" of the 16" Dodge/Plymouth rims used on cars through '48? Not asking about the hub center, but the actual OD of the center stamping where it is riveted to the hoop. I don't have access to a wheel to measure at the moment. I am looking to run a wider hoop (like 5" or more) than the stock 4" job. I know there are factory 4 1/2" wide rims available, like from pilothouse trucks, but ideally I want to go at least 5" wide. And since I am already here, has anyone welded up wider hoops specifically using the 16" Mopar centers? What donor did you use for the hoop?

 

I measured two different styles of early 16 " mopar/dodge wheels and they were both 13 1/2".

 

Thanks 117--I think the 15" riveted rims are around 12 5/8", so that sounds about right. Now to research donor hoops.