Nice find My guess is mechinical im no expert and dd are not my strongsuit but i need to concere this and become a expert because there is money to be made and lots of it
Take a look at varietyvista.com and look if the die markers match up with that 1958D DDO-001 http://varietyvista.com/01a LC Doubled Dies Vol 1/1958DDDO001.htm
I compared also i see what i want for you to be a dd but it drives me crazy because im such an optimistic person my bad you need to ask a pro dont make the mistake i did and put a no mint s proof mark dime back into circulation it still to this day knowing what ibknow kills me