Warren
You are right. The NSN for the military junior is 2940-141-9025.
Here is a link to the NSN search which gives manufacturer's numbers:
http://www.dlis.dla.mil/webflis/pub/...9025&newpage=1
One of those on there is the C21P (a familiar number), which I translate over to the NAPA 1100.
In all honesty though, either will work. The 1100 has a more surface area, but since it is just a partial flow oil filter, if you ever were to actually plug the filter, your engine would likely already be toast. About 15% of the oil goes through the filter while the other 85% goes directly to the bearings.