Sounds like you are in pretty good shape. One thing you can also check just for more knowledge is to measure the top of the piston Dia. as well.
No idea on the DN4M pistons, but many other pistons have a slight taper to the piston, smaller on top, larger at the skirt, only by a few thousands.
I'm sure you already know, but especially since you are at only .002" gap, make sure to check your ring end gaps to be sure they won't bind up in the cyl. when they heat up and expand.
When you reassemble, stagger the end gaps, oil the rings and rotate them around the piston to distribute the oil into the grooves before installing them too.