I'd suggest modifying a real Vise Grip brand tool by cutting off part of one side of the clamp and welding on a piece of rectangular stock the right size to fit the T slot accurately. Of course, I've always made specialty tools rather than paying outrageous amounts for work I can do myself. Most of my dedicated automatic transmission assembly/disassembly tools are home-brewed.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!