Ouch! Thats bearings been bad for many miles. You will love how your bike rides and handles once it back together.
I'm normally a 'save it' kind of guy, but in your case I would add a replacement swing arm to the list for sure. It looks like the depth dimension of that standoff (basically a built in spacer) has been compromised.
The way the spacer/axle/inner bearing race is clamped together, that dimension is critical for proper bearing torque without side loading the ball-bearings in the wheel. If that dimension is shortened like in your case (or more commonly a over-torqued spacer), the outer wheel bearing races will bottom out in the wheel and you will continue to have pre-mature bearing failure until you fix it correctly. Usually mis-diagnosed as 'Brand A bearings suck, get brand B" when all you need is the correct space dimension.
Follow the manual instructions exactly for proper torque, and procedure and you'll be OK. Get that .pdf download for free at Buellmods.com or Buelltooth.com. Hows the wheel hub look? Was the rear rotor over heated? Are the rear pads worn crooked now?
IMO, I replace wheel bearings every time I put on new tires. Barely any extra labor and worth the small parts cost for 'trip insurance'
Check the classifieds here for a good arm or PM Purpony, he usually has a bunch of good parts and is a stand-up guy
TL;DR
Replace the arm.