I have a sigma dm-35 solid top back and sides. The headstock has custom on it no sigma emblem. It was made in Korea has a paper label inside the sound hole. I have never found any info on a custom sigma however I have one. The grain on the inside back and sides match the outside and the top is one piece viewin from the edge of the sound hole. I bought it used back in the mid 2005 to 2006. It is in almost mint condition but the tuning machines have been upgraded I believe. I bought it from and old man who owned a small music shop and at the time I was going to buy a blue ridge but he said this was a better guitar and I paid close to 200.00 for it used. Never seen or heard of another custom sigma. If anyone has info please share. It is a very good sounding guitar with great projection. Spruce top mahogany sides and back. A definite good find and a real keeper. Thanks
James D.