My new Mystery Mold

I just got this mold. It's a copy of a Pope 311403. I haven't cast with it so, I don't know if it has the large base band but, it's marked .309 V or X 301 E, with a electric pensile. What I'm most interested in is, who made this fine mold. It's has excellent craftmanship. The mold cavity has a excellent finish and who ever made it, used a shoulder bolt for the pivit and a 10x24 button head for the stop. The sprue plate could have been thicker as, it's only .110 but, the bullet side is ground. The sprue plate is stamped out, to me, that saying, he intended to make a lot of them.   They are 1.500 x 1.375 x 1.490 long. The width between the mold handle cut, is quite wide @ .870. I have a lot of different mold blocks but, none measure as these do. With the width inside, where the mold handles go , a 60 caliber mold could be easily done.Any ideas? Frank