aw man, and here I thought you painted that on by hand LOL Umm well as for technique it all really comes down to one tried and true for me and that is MIG pigments. I'm not sure based on the pics if your Arty piece is OD or a shade of Grey. Either way there is a fading powder for Olive Drab and for Panzer Grey, which to be honest works with most if not any shade of dark greens and any shade of grey. A wash or two would blend those letters in too, but you have to wash the entire surface in a series of light coats of devlan mud... I guess that's a glaze eh? Hope that helps man!