This is the real question. 

Is this eBay seller in London, with a 100% good F/B rating, who happens to say that they are selling off all their late mums things,... really on the up & up?  I would like to think that this eBay seller is,... as they themselves say they are not all that knowledgeable and a little ignorant to the fact of what they are selling, while not having much knowledge of the world of fine art. Fortunately or unfortunately, which ever the case,... this world of ours is filled with skeptics,.... and with good reasons.  some would have the tendencies to believe that they were just trying to pull the wool over their buyers eyes and scam them out of their hard earn cash. It is a little amazing how their mother had all these fine works of art in her possession,... and without her children's knowledge. 

Let us just surmise that these in fact were a few pieces of original works of art, supposedly collected up by their mother,.... probably over her life time, while having no idea who the artist's really were, not really caring or knowing their actual value or worth.  What the MFA art experts fail to realize, most these famous artist of long past times, had one hell of a time trying to sell their works of art, when they were living, and if they had to depend on selling their works of art through these MFA people, they would have died a faster starving ass death.