Zinc Chromate primer is a green primer used in Aviation to prevent corrosion. That is what it looks like on your rifle. Whether it is or not I don't know. However it would make sense to use it.
too green, zinc chromate is alot more yellow
its interesting to see how much paint was used, the regulations sad only parts covered by wood would be painted, but in truth it varied from not visible with the wood on, to this




















































