Sigh... I hear you! Everything art and handmade related is so difficult to sell. You have to pay so much money in advance to promote your product and you will never now if the investments will pay out. "Taste" is so subjective and tough to calculate... Sadly I am of no help, because finding a target group which is willing to pay is not my expertise.
I think @jamethiel and @shanibeer wrote very helpful things. I could only add that maybe locations who use special furniture could be an audiance ... meaning not the players at a festival are the buyers but perhpas the people who equip rooms/houses/tents for the storylines.
I hope you soon find a good way to sell your lamps. You deserve it, because they are unique works of art!!!
Looking forward to your new work <3