Hiya, I took a good peek in the bothy in the last half of last year. It is split into two sections. One half is just a run down cobbled floor, but it looked like work was being carried out to it. In the other section, was a park type bench and I counted the beds, but for the life of me I can't remember. There are at least two - four if you are lucky, but I guess the park bench might come in handy.
Looked like a good bothy to me. You gonna bag the corbetto while you are there? I didn't realise it was there, so will no doubt be heading back up there, but probably not for a number of years yet.
Have fun and let us know how you got on - one of my friends recommended 'crackle logs' or something from Morrisons supermarket....????? (Apparently they are light for carrying in).