Actually there is one the 1905 that is an ddr and yes the doubling looks very simular to the shield and oak leaves on the op coin.
No actually it is a learning process trying to remember varieties you have seen,and how some may be questionable. As there are varieties that in fact have been proven to be false and not a variety but are still considered a variety. Longacre designs are very deceiving at times...shield nickels especially.
I don't believe it's a DDR. If it was, I think you'd see quad stripes inside the shield, which I cannot make out. My opinion is machine doubling.