That's a prototype mule, so the wear might be exceptional. By the last days, though, some planes probably had patches as used as that.
Caption for 167 in the Czech book reads:
"WN 167, Straubing, undoubtedly JG301, 1945"
Předposlední vyrobený stroj o jehož bojovém nasazení vypovídá značnně opotřebovaný povrch křídel u trupu.
Penultimate made machine ("o") which/whose (martial) (deployment/setting) testifies well/substantialy attrited surface (wing/aileron) and fuselage.
The profile looks like it was based at least in part on
this picture. You can see the wear that the profile shows there.
I'm not sure if that's really a different band of color on the tail, it sort of looks like it's just damp with some liquid. Or maybe they used whatever random paint color they had on hand. It doesn't look like green, which should be lighter than #81, not darker as on the picture.
The doted shading on WN003's horizontal stab is bare metal.
