I need to know the value of A Lumen Winter painting or Litho. It is 18 inches high and 23 and a half inches wide. It appears to be hand signed. Four white horses running. Top background is red and fades down to purple. I've searched websites of his work and can't find this painting. I think it is a Litho because in the bottom left corner, it is hand written 127/260. The signature is in the right corner.