This is a little unusual in the Tortoiseshell being rather red. They used silver nitrate to turn red glass into brown, this one missed out a little on the dose of silver, but it's a nice feature.
The pieces with an "artist signature" were not signed by glassmakers, but by Marie, Vicente Boffo's niece, who also got the job of packing stuff up, or by Eric Dobson, the manager.
Unless they're one of the odd bits that got signed by Michael Harris under request. He didn't like signing his work.
But in the mid-70s, some pieces did get deemed good enough to seem to have an artist's signature, so some were put on, by Eric or Marie. We don't know what it's supposed to read, if anything.