I got to grind on this for a few minutes tonight and made a little progress
I figured out the "bottom" is welded a lot lower than I was originally thinking.
I held the grinder right above the weld line that I could barely see from the inside and was able to take out a few pieces at a time.
Looks like this might work with a little more patience and a flap wheel to clean up what I can not get out with the grinder/cut off wheel.
What I got out so far....
This is a close up, looking up the keg wall, on the left you can see, barely where the weld line and I was cutting just above it with the grinder -
Getting closer.... this is getting easy
Now I just need a flap wheel.
Are there different grits and types of these wheels?
Maybe one that will work on a big drill?