Boys 55 Cal. Original WWII Tool Broad Arrow ?????? (WHAT IS IT) ???????

Description

Boys 55 Cal. Original WWII Tool Broad Arrow ?????? (WHAT IS IT) ???????
-I have had this for over 30 years. I've sold off my Boys long ago and found a large bag in my garage filled with Boys parts, tools and 700 rounds. I don't know what this is for, I've tried for what seemed for hours when I had my old ATR. The tool is in fantastic condition. Two Broad arrows cartouches are present as well as "RIFLE BOYS MKI". The threading is perfect. Well oiled, machine screw travels great in and out. The front nipple on the screw pivots just fine. Funny thing, the makers of this tool put a broad arrow on the end of the nipple (strange). I had another Boys tool from the factory long ago, and the factory spelled Boys, Boyes.
-Very heavy, about a pound and a half.
-Heavy, robust, military tough but what is it
-Shipping: Possible very late delivery to your area due to covid and lay-offs
-See photos for they are the best description of condition
-Paypal only or whatever Ebay is taking-No International sales- .00 Shipping & Handling