My Jeffery 6.5x53r has this type of front sight/hood

Looking at the hood on your rifle, I can see two pins on the image of the right side of the hood.
My guess is that someone has 'permanently' pinned it in place, possibly in the effort of a refinish job.
Your sight/hood might have had the QD feature from the factory.

The forward-facing screw-head doesn't secure the sight blade does it?
I think that on my rifle it has to do with the QD mechanism.
My factory record page is buried in storage right now, as is the rifle.
If I can dig the ledger page up I will compare serial number ranges with you and see if I can assist in getting you somewhere close to a build date.
As I recall, the gentlemen accidentally sent me two pages, one for my rifle and one for a rifle made in the '20s

We shall see...

Cheers
Tinker