i bought a sigma DM-5 in the mid 70's i dont remenber exactly i cant find the bill of sale but i do have the original show room tags.It was bought at a martin dealer in a little town in southern BC,Canada called Langley.i played it constantly for many years and then it sort of was retired.my interests took me in other directions.recently i restrung it after not touching it for almost 8 years.i was amazed at the temper and warmth of this obscure beauty.she is as stated a DM-5 with a relatively low unique serial#3333.does anyone know how to zero in on the manufacture date.i have read a lot of the posts starting from 2004 and MR.Web has the most revealing info.