1956 Roosevlt Dime RPMm

looks like Machine Damage to me.

I agree. How can we tell that it is machine damaged after the strike? Note the bottom SE loop area of the mint mark. You can see the overall normal size of the devices at the bottom of the mint mark. The top 2/3s of the mint mark is reduced by MD after the strike, damaging the mint mark. You will note how the width of the top of the mint mark is thinner on the side affected. That is how we tell.

But I would like to see an image of the mint mark area a bit more looking downwards of the center? There maybe something we are missing there?

I don't see an East RPM on this site:
http://richardsrooseveltreview.net/1956.htm
But there is a very nice doubled die shown for that year that all might want to look at?

Variety Vistas RPMs for this year:
http://varietyvista.com/07%20Roosev...%201956D.htm

Note on the top of the mint mark, the contoured design of that device? That should be seen on the bottom of the mint mark as well. But it was damaged after the strike, flattening that area. Now it shows damage on the mint mark. So rather than contouring like the top, the bottom is now a shelf edge, straight downwards. No contour. Just like all machine damaged devices will show. Not a RPM.