Anything that fills in behind the trigger guard will keep your middle finger from getting whacked. Nothing wrong with the T-grip, and when he says that they've been around for "awhile", that he means since the '50's.
FWIW, I recently went to the Pachmayer Gripper model on a 3" 60-15 and couldn't have been more pleased and surprised. I've never been a fan of finger grooves on a combat revolver but these are great. And the rubber works with the all-weather aspect of your 60's stainless steel. You might see if someone can let you try theirs before you buy.