From what I understand, the opening event is ticket only, and it sold out weeks ago. You will be able to go along after the opening day, though, but only when the Museum grounds themselves are open. So it's limited hours, then.
It also struck me that if all the people who claim to have drunk there actually did, then it might still be open, because the place would have been packed every night. Mind you, who needs a nice old pub, when you have a car park to build?
Personally, my only memory of the place was going past it on Sunday lunchtimes, and seeing rows of black motorbikes lined up outside. I haven't seen any mention of this anywhere else, but for a long time during what must have been the seventies, it was the regular haunt of local biker gangs.