Nice Cart. It looked pretty bad on EBAY but your photos show that it was not a pile of rust.
Here is a tire that would look pretty good on the cart. This is the same tread pattern found on 18" Cart rims.
http://www.cokertire.com/400-19-coker-c ... tread.htmlThe correct tires are 19" with the chevrons in the middle.
There are also a couple of carts with this pattern tread, but the tires are dated 1951.
Anybody want to step up and claim this cart so I can put it on my list.

The Lunette is almost identical and you shouldnt even give it a second thought using Ed Snyders reproduction. Everything is welded together instead of riveted like the M3A4 so its actually an easier build.

I dont have a better picture right now but the Tongue would be pretty easy to fabricate.

As far as rims I do know for sure that 18" cart rims are Harley. 18' rims will either be Interchangeable or 45 rims. I cant say for sure if the rims on the Marine Carts are Harley. Just never thought to research that yet.