Old Mill Stream

I have a painting from Windsor Art Products, a division of Illinois Moulding Co., Chicago, IL.  There is a serial number of P503 246 and an artist signature, "Paul Detlefsen".  The painting (including frame) measures approximately 44 1/2" w x 28 1/2" h.  This was my grandmother's painting.  Now, my mother's.  My mother is not sure when it was purchased.  She's not sure if it wasn't purchased my her grandmother. 

Photos are attached.  The frame is intact.  A photo will show the one flaw on the painting  I was able to find in the upper left hand corner.  The paper on the back of the frame is showing wear and tear.  Otherwise in very good condition.

We may be interested in selling, not sure yet.

Please let me know what you think.  Thanks in advance.

Fair