yes
There is no record of an artist named Charles Greer. It's possible that he may have been a very minor artist whose work was popular at one time. There is a Charles Greer who was in the Marines in WWII who won the Silver Star for his heroism. He had a ship named after him.
Artist proofs tend to be more valuble due to the fact there is usually only 1 or a couple, and the fact the artist printed it with his own hands.
Yes, many of the paintings are very valuable. Many of the paintings are worth a price close to $3,000 each.
If the etching is one of a kind, I recomend looking for the name of the artist on the etching. If there is a name, you can look up the artist and get a general idea of what a piece of his/her art is worth. If there are more than one sculpture/etching of this same theme. Try to find the price or value of the other.
Charles Burchfield was an American painter born on April 9, 1883. He was well known for his watercolors of townscapes and nature scenes. His largest collection of paintings can be found at the Burchfield Penney Art Center in New York.
Printers Proof's are most of the time signed by the artist, but are most of the time not numbered.
Charles Hubbard - artist - died in 1875.
Charles Barber - artist - died in 1854.
Charles Barber - artist - was born in 1784.
Charles Dixon - artist - was born in 1872.
Charles Dixon - artist - died in 1934.
Charles Ray - artist - was born in 1953.
Charles Gough - artist - was born in 1784.
Charles Ross - artist - was born in 1937.
Charles Martin - artist - died in 1934.
Charles Martin - artist - was born in 1884.
Charles Hubbard - artist - was born in 1801.