Hi,
My brother has a record that he bought almost 5 years ago from a closing down record store in London, UK.
It has two signatures, Michael Jackson and Quincy Jones but no photographic proof or COA. The signings are alleged to have taken place on separate occasions (no specific time or date stated) whilst the store owner worked at Virgin Radio. This is as per the signed note included inside the record sleeve.
What are the chances of either signature being authentic please? Images below. Thanks for your help.

