Blown amethyst double chambered, footed vase

This vase is about 10.25" high. A $.99 thrift shop find today. It is fairly thin glass at the top progressing to 2 or 3 times that thickness at the bottom. It is pretty dark amethyst and challenging to photograph. It looks like a simple vase, but is a bit more complex than the run of the mill bud vase, since it has two chambers. I don't think this was a one man job. The pontil is worked fairly smooth and doesn't immediately bring to mind a particular glass maker, but I think it is probably American and maybe a couple of decades or more old, despite the fact that it shows almost no wear. A google and ebay image search did not bring up any similar vases. I am searching the catalogs of American glass available to me.