terms

There is very little info about this competitor for the Schnellbomber competition, but it seems pretty close to the Mosquito in terms of performance: https://en.wikipedia.org/wiki/Henschel_Hs_127 I was curious if anyone had any info about it beyond what's in wikipedia.

I'm a little confused over what the "-20NA" means in P-51D-20NA. Also, what is NA-122? I've seen both of these terms used in a lot of places, but there's no explanation given as to what they mean.