Hi,
I can't be of much help on the older eye bath, but you are correct about the blue opalescent one being by Rosso. These were made as plain utilitarian items originally, so if you see one done in any sort of art glass it is likely a reproduction by Mosser, Boyd maybe, Summit maybe or one of those other companies who produce this sort of stuff. Rosso has all of their glass made for them by Fenton or one of those other makers. --- Mike