I cant be sure about Bri, Rog and Deacy but Im pretty sure the Freddie signature is a bad forgery. In the F, he had this thing he liked to do where he would cross over the F to make the R. Also the M in Mercury is nowhere near on. The Y is pretty good but the rest is shotty at best. It may be a post 91' thing signed by all 3 after Fred died and then a forgery for Fred. Brians looks OK but not very well. The B is spot on, the rest Im not sure about. I would find out the history of this item and see if its fishy.
"Fuck today. Its tomorrow" - Freddie Mercury