Hope I am not misleading you but, I have necklace and bracelet almost the same from Taxco, Mexico. Number belongs to the silversmith who made the piece I found out, while the T is for Taxco. Check into that and you may find your answers. Pretty set regardless!
It is Taxco Sterling silver from Mexico. The T-# stamp is the referenece to the local(taxco region) and the numbers are the registration issued to the silversmith. Unfortunately you have waht is called a mixed medium inlay. It is a mixture of plastics and block turquoise or again plastic. It is getting hard to find modern examples of this inlay that actually uses real stones. This jewelry has a following and people seem to like it. You can find plenty of it online and the prices fluctuate alot. You can look up Taxco Inlay panel necklace and find it. I have not had much luck selling it. Unless it is from a known silversmith from the 1930s and 40s it tend to move very slowly.
The only thing that you can tell from the hallmark is that it was made post 1980. That is when the Sterling Hallmark letter and number system came into being. Billy Hougart has a book called the little book of Mexican hallmarks. If you can read the number after the T I can look it up for you.
Thank you for your information. The letter following the T is either a J or W and the number is 37. Maybe that will lead you to more information and a name. i looked closer with a loupe and it seems the tourquoise is real? But then again I am not an expert. Any further info is appreciated. Thank you.
What i liked is that it looks to be a matched set and has 3 pieces. Best. Ed