After looking at all of the possible variations on artists with the name Munch, it appears the most logical choice is:
Gustav Heinrich MÜNCH (1884-1922)
Gustav Heinrich MÜNCH-MUNNTYZILL , Gustav Heinrich MÜNCH-MANNHEIM. He signed his name in several variations on these three names.
He is the only one with a name that follows the Munch.
The artist is primarily known as a landscape painter. Which is why I had some doubts.
Next is how the value of the painting.
In today's art market the importance of the artist drives his market.
Gustav Heinrich's art is sold primarily in Germany, where he is best known. In tracing the auction records for the last 5 years, his paintings have sold for: $244.00 to $306.00. This give us an estimated value range for your painting.
Thank you for an interesting challenge.