We were in Liverpool last week and amongst the exhibits at The Beatles Story was this guitar, so I contacted Diane and Johnny for more information and they both replied within a few hours.
From Diane Lee - "Firstly the Flying V is not a Gibson, an error. I donated it to the Grammy Museum here in L.A along with one of his harmonica's and a few other items. When they had it on display, this is the caption they put with the guitar.
Back in 1993 or was it 1994? 93' I think. Arthur gave the guitar to Melvan who played it & took care of it the best he could. The neck got broken along the way. We had it repaired at True-Tone where the guys gave him a lovely case to go with it. Then in (?) year I bought Melvan a new Gibson Flying V as a [trade] for the other so that I could donate it to the G Museum. Apparently at one time it belonged to Johnny Echols as well which I did not know until recent years when Johnny said so. That's the story."
From Johnny Echols - "Actually it's a Carlo Robelli flying-V guitar that I traded to Arthur back in the seventies. Diane loaned it to the Grammy Museum".
