OK there are not much for proof marks under the action. On the barrel just ahead of the recoil lug is the letter V
On the action flat right behind the recoil ring is the letter N or could be a Z in a circle.
Also in this area is what appears to be the letter L the verticle leg of the L has a half circle on it to make what appears to be a D and then off the end of the horizontal line is what appears to be an upside down number 8 which is at about a 20 degree title off verticle.

I tried to get pics but was unable to get clear ones. I had to use a magnifying glass to actually see the markings.

So have at it folks and let me know your thoughts or questions...

Thanks,
Don