54 F120: The interfordal Restomod.

I though anything with a removable steel ring was considered a widowmaker.

Widowmakers are semi drop center wheels. The wheel is split in two like a bagle down the center. Neither 1/2 is split like a lock ring. The two halves have to be assembled like a telescopeing cup The flange in the middle has to lock together.
Lock rings are completely different. On lock rings the tire bead goes over the ring and forces it deeper into the lock groove. If the wheel/rim in question is not severly rusted or bent, a properly assembled lock ring wheel can not come apart. The ring "wants" to fit into the groove and the tire bead going over the ring make it impossible for it to come out once the bead has been seated by 10-15 psi in the tube.
The thing to watch for is bent lock ring, This is most often the result of improper dis mounting procedure. The bead of the tire must 1st be compressed away from the ring. If you try and force the ring out without compressing the bead the ring will be distorted and should be replaced.
Widow makers gave all tube type rims a bad rep, but they are not all the same. The same amount of energy is stored in a one piece rim as is stored in a multi piece. You must use respect when dealing with that much stored energy. If you want to know how much energy is stored, try inflateing one with a hand pump, you'll get the idea real quick!
I've change many lock ring type rims and never had one come apart (more then many tire tech). I've dis mounted and repaired flats on the side of the road, where the nearest help is 150-200 miles away. The is nothing wrong with lock ring wheels but before you work on one, have someone who knows teach you. Not all tire shops that work on them, know how to do it correctly. Most often tire shops that work on large earth moveing equipment or farm equipment have the proper training. You should never "beat" on the lock ring (a practice I've seen some tire tech do) to seat it. The ring should seat itself if properly assembled and not damaged.
Although not the OSHA approved method, I service these type rim without a cage or chains. I prefer to KNOW it is going together correctly then to have some cage try and protect me from a bad mount job. The time to find out if it is assembled correctly is when it doesn't have enough stored energy to do any harm, cages try and contain the blast after the energy has been stored. Far to many assemble, roll into the cage and clip on an air chuck and walk a way. That is a way to get killed, just because it didn't blow apart in the cage doesn't mean it seated properly, and then they roll it out and have no protection. The cage isn't the problem (or even the lack of one) but improper procedure is what kills. The time to look for proper assemble is with 10-15 psi not 100!
All this only applies to lock rings. Widow makers assemble different and there is no good way to be sure it is locked and will not come apart without putting yourself in harms way. That is how and why they got the widowmaker name.

much more eloquent than what I said. I knew you would have a better explanation. Proper seating, proper care, good equipment= life time of good service for you. As CB said, rarely is there a mishap, those are cause by improper handling and not making sure it is right at the Low pressure first. That said, I have a health respect for these wheels, I was in a Military shop when a ring came off, that was the last mistake the fellow ever made. Still dream of that occasionally. Happened 40 years ago. Millions of miles on those lock ring style wheels.

Same here Ibesq, I heard one outside, the wheel was caged, and I was 30 feet away... i still hit the dirt.

to get somewhat back on topic. Parts are coming in this week. Got the gas tank ready to go back in. Should get a bunch of stuff installed and have some pics to post. After all that, banging some joints out and looking for a conversion joint if it exists.