This is very clearly not a GE J-105.
Think that's a '50 in the back? I don't know too many other huge globe-envelope tubes.
Edit: I think it's from 1932...and GE apparently re-used their model letters. RMOrg doesn't have the J105, but has a 100/107/109 and all use the tube line-up 58 58 56 58 56 56 46 46 82 56. Mystery most likely solved.
The seller is delivering it to my house later today, so I removed the Craigslist link, sorry :p