No, it is not a doubleD die. If you think the mintmark was doubled (repunched) that is not the same as a doubled die. Back then the mintmarks were punched by hand after the working die was completed so any doubling associated with a doubled die would not appear on the mintmark.
And it is not a repunched mintmark, it is called "plate split doubling" and is damage. Here is a good reference for non-doubled dies that can appear as doubled dies. http://koinpro.tripod.com/Articles/OtherFormsOfDoubling.htm
