That's Man-O-War, an 8-station Star-type tool for .50 BMG built by Jon Powers in Michigan for me circa 1985. Jon built one for himself first, then Kent Lomont talked him into building a second one, then I talked Jon into building a third one for me.
Kent had a fire in his shop in Indiana and the tool was damaged. I
think Jon rebuilt it but I'm not sure. I heard Jon's personal press was stolen some years ago. Mine is the only surviving undamaged one with known whereabouts.
Jon is a machining and designing genius, IMO. He designed and built a half-dozen or so
Powers Magmatics, a gas-operated semiauto .44 Magnum that was a thing of beauty. He patented the gas system and either sold or licensed the patent to IMI, who then came out with the clunky (and wrong grip angle) Desert Eagle.
FUN FACT: Jon tried to test one of his pistols to destruction, and was unable to do so using available components. He'd melted case heads and had to scrape brass out of the bolt face, but the gun always held together with no measurable dimensional changes.
Jon called me one day to tell me he'd finally succeeded. "What was the load?" I asked.
"A 265 grain Hornady JSP over 22 grains of ditching dynamite."
JR
Edited to add:
HERE'S another thread from a few years ago with more info on the Magmatic and Desert Eagle.