Mystery rear rim on my 2n

[Harrison9N]

I've got a new-to-me '47 2n that I've been bringing back to life, and I've got a mystery on my hands: The left rear rim is standard OEM with six loops for 5/8 inch bolts. The right rear rim confuses me. Not the same. No loops. (See both photos of mystery right rim, but ignore the leaky seal.) What am I looking at, and where can I find replacement bolts?

 

[bob p mn]

The rim pictured is the standard factory rim which is usually referred to as a hat rim. The rim with six loops would be a replacement rim. I usually source the bolts from an aftermarket parts source they sell them just for that purpose.

 

[Harrison9N]

Many thanks for your help.