Yes, It is looking expensive and am trying to source a used swing arm, The double row SKF 22.2mm wide bearing looks to be the best option as you are very correct that there is not a lot of the body left to retain the bearings.
I was very careful when seating the bearings & not driving them home too
hard & the machining was checked both ways as to not take too much out.
I also cross referenced it before & after the mod to check for myself that the overall width had not changed.
All I can put it down to is having really good traction, damp rocky loamy ground, steep smooth hills for a long period, lots of erosion mounds, a KTM 525 just in front of me, landing off the erosion mounds then powering on hard with the wheel getting driven into the ground hard getting maximum traction & little slip in second- third gear putting huge loads on the hub.
The hub had near no play in the rubbers as I checked it the day prior riding in the Snowy Mountains, I will get it apart again shortly & add some more photos, The 2 photos that I put on in the first note are when I got home after recovering the bike & putting the wheel & hub back in the correct position. All I can say is if you have the double mod done is to keep an eye on it especially the alloy casting inside the hub for any signs of cracking off the retaining section that is about 2.5 mm thick approx.
All I hope is that I can help in that we can all learn from my misfortune.