Looks like mechanical doubling IMO. Not a doubled die. Further, the large date over small occurs on proof cents, and yours is a business strike, so it cannot be the doubled die you suggest it is.
Hard to see really, but non cents does bring up a valid point that the Lg over sm date was proof only. However if you can get a picture of just the date and enlarge it that would be best.
I find the easiest place to see the large /small double die is with the "zero" of the date, and I don't see it here. Here is one of my 1960D DDO, D/D RPM small over large. Notice the zero. Yours doesn't have a such appearance or even the opposite. More at this URL. http://www.lincolncentresource.com/doubledies/1960Dddo1.html
