Chinese Emperor "Reverse Glass" Oil Painting /Circa Mid 20th Century

I found this at Volunteer's of America the other day. It's a reverse glass oil painting of a Chinese emperor. It's about 14 " x 22 " in a black lacquer frame with a fret work brass hanger. The back is sealed with a panel of thin wood. The painting itself is in very nice condition (no peeling or flaking) although the frame is a bit grungy. There is a label on the top by the hanger the says "Made in the People's Republic of China". So that dates to late 40's to the mid 70's. There was likely an Empress to go with it but I didn't see it anywhere in the picture stacks. Maybe it was put out before and sold. I really need to go back and check to see if it was put out after this one. A bit surprised at the value range of these. Pairs can bring a few hundred dollars but it also depends on the age and condition. -Mike-