Their looks to be doubled die on the chin and nose and on the 9. I know it's very circulated though. But is it doubled?
MD (Machine Doubling) is a mint error but unfortunately it was a occurrence that happened all the time, so there is no real value to them. Although there are a lot of people that collect those I have heard them referred to as a poor man's doubled die. JMO Dave
MD is not DD you should go to a cent website and write down all the DD pennies out there. Then you'll have a list of which years/mm to look for.