"The fact that the Stone of Odin once had a twin right next to it surely puts an end to thoughts of handfasting or whatever dating back into Neolithic times, too little room."

What's "right next to it"? Slap bang up against it or 1m away? Also what height was the other stone? If short then it wouldn't get in the way. Which way did the hole in the Stone of Odin face, towards the other? Also are the two sockets contemporary? Did the Stone of Odin fall and get re-erected in a different hole?

Not supporting either theory here, but a socket is not evidence to poo-poo the other theory completely.