I painted on layered glass during the 1960-70’s. I created this technique and process and all the paintings were original works. It’s difficult to produce and could not be mass produced.
I had a wonderful rep who, with his team, placed my work in stores throughout the United States and Canada. They were very popular and sold well. Most of these were of flowers in sizes 4×4,” 6×8,” and 8×14”, painted on six layers of glass. I painted just a handful of larger paintings (16×20″) like yours for special orders. All of these larger paintings were of flowers painted on 6 layers. You have the only scene. It is one of a kind and I’m happy to see it again.
I have spent the rest of my career painting portraits of people. (Including Santa which has also made me well known). My glass art work is growing in value and I frequently get inquiries like yours. I don’t have suggestions on what price to ask, but yours was painted on an expensive thin plexiglass and is lighter weight and less fragile. The only glass is the picture glass on the top.
Your frame looks in great shape. They can pull away at the corners – this one looks tight.
I hope this helps.