Other than trying my luck at salvage yards, etc., do you know of a source for 9 x 28 6-loop rims, with the original “rounded” loops, that use the “keyed” or “pipped-head” bolts to attach to the centers? The aftermarket rims all have larger, squarish loops, that use carriage bolts. I only had to replace one of my rims, and the old one uses the “keyed” bolts, which are still available. I’d like the two rims to match, but that may not be possible, unless I get lucky at a salvage yard. (Maybe I’m just being too picky!) I read your informative article on rims at the FENA site, and it was very helpful.
Sorry, as far as I know the original loop style rims are no longer available anywhere. Salvage yards are your only option. The aftermarket rims with the squarish loops can be used with the original keyed or pipped-head bolts but, you will usually have to hold the head with an open-end wrench to tighten them. Also, the aftermarket rims have the valve stem hole on the opposite side of the rim. With the original round loop rims the valve stem hole is on the outside edge of the rim when the rim is in the “Standard” or 52″ setting.
The aftermarket or Ford style rims will have the valve stem hole on the inside edge of the rim when the rim is in the “Standard” or 52″ setting. As for the keyed or pipped head bolts, the original part number 180 876 M1 are still available but, you can also use the slightly longer (3/16″) 828 217 M1 bolts which sell for a fraction of the price and are readily available from after-market suppliers. I add a hardened SAE washer under the nut to take up the difference in length. This washer is the same one used on the Ford 9N, 2N, 8N and NAA. Of course you can always use the Ford style carriage bolts. Those are readily available from after-market suppliers as well.