Question about the "ZF" buttstock marking

Hello everyone,
I was looking over my No.4MKI rifle while reading a post on these forums about the "ZF" stamp. With a Google search, all of the examples of this marking I've seen are stamped on the right side of the buttstock near the buttplate and the "Z" and "F" are together.

However, on my rifle, at the bottom of the buttstock at the neck There is a "Z" in one spot, an "F" in another and a "BH" in between.
Is this considered a "ZF" marking? Or can it be ignored? What does the green paint mean as well?

Attachment 51765Attachment 51766

I bought this rifle a while ago and I haven't really shot it. I tested it once and only put maybe 10-15 rounds through it without flaw. After I bought it I noticed that the extractor on the bolt head was missing and the store I bought it from replaced the bolt head and did a headspace check. I found this to be weird. Why would the extractor on the bolt be missing?

Any thoughts? Nothing looks/feels wrong with this rifle. Is it safe?

The ZF on your rifle aren't the same as what we'd define as ZF. When we do it is close together and indisputable!

Extractor missing......... maybe someone stole it as a spare.......