For what it is worth:
There is a new casino (for me) in Leichester Square
called Empire. You have to be a member to enter but
all you have to do is how passport or drivers' license
and then entry is free for members.
In the past, I recall having to have coat and tie to
enter but I entered wearing a sweater this time.
Slots and table games but I did not see any videopoker
machines on a quick scan. I do not know if this is
true for other casinos in London.