Hello and welcome.

The broad "sideways" script on the base would put this to somewhere late '70s early '80s, I think the colourway is probably Tortiseshell, deep reddish browns.
I'm afraid we don't really discuss values here, they're far too subjective, but I can tell you it's not really worth a lot.
Michael Harris left in '71, although they did carry on with his designs and with variations.
This is a little unusual, not a major production shape.
It is still a decorative, retro piece of Mdina, but I'm afraid you are not looking at being able to retire.