I'm not sure about Black 6's flyable condition; I suspect it's as close as it can get, but I don't know. Russ Snadden was/is pretty exacting, so might be. It wasn't officially struck off RAF charge until about 2001, I think.
As for the LVG, I was at Hendon when all the hoo haa about it not being flown again in 2003 erupted. I went to the last Shuttleworth show the LVG made a public appearance at and it was ground run, but not flown. The SVAS guys were slagging off the RAFM to anyone who'd listen and frankly I was a bit peeved at what they were saying since it was a load of BS, so I told one of them I worked for RAFM and that shut him up. When I got back to work I told some of the head neddies at Hendon what was being said and as a result they put out a press release in the aviation tabloids (Flypast and Aeroplane) stating the situation, that the aircraft's lease had expired and it was Shuttleworth who had agreed not to renew it.