Vintage Taxco Pig Brooch Abalone Inlay Pin

Fun vintage Mexican silver and abalone inlay pig brooch with a puffed out design and impressed details. It's hard to make out the mark on back, definitely says "Taxco Mexico" around initials that look like RCB, but I can't read the whole thing. There's also a Taxco eagle assay mark with number 3 inside, for Taxco. It could be sterling silver but looks more like Alpaca (nickel) silver. I'm not sure. There are some spots of tarnish but he's in great vintage condition. 1 1/2" x 1".