Looking for authentic Queen autographs preferably John Deacon

I've started collecting autographs and have been looking for John Deacons, I know it's rare and there are likely to be a lot of forgeries, anyone have any idea where I could find one. I do have this one in mind, it is authenticated by Beckett and I looked in their database and the numbers do match https://www.ebay.com/itm/John-Deacon-Signed-Autographed-8x10-Photo-QUEEN-Bassist-Beckett-BAS-COA-Proof/264306048206?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160727114228%26meid%3D1cd3c870dfe6440c8652ea444bca358e%26pid%3D100290%26rk%3D1%26rkt%3D4%26sd%3D264306048206%26itm%3D264306048206&_trksid=p2060778.c100290.m3507

I wouldn't recommend buying autographs, and would add that John's autograph has changed over the years.
There are loads of bad genuine ones about, as well as good forgeries with ''certificates'', so it's a real minefield.
I have some I got from John directly in '76 and '84 and they look quite different.
I can post them here if you want to use them as a guide, but ultimately you are taking a gamble unless you get one yourself.
Don't bother to ask anyone on here to authenticate either, they are simply guessing.

This is a great article. It gave me a lot of useful information. thank you very much.
http://picbeauti.com/qnovias

link doesn t work