Do you have wood stocks on your 605? If so you remove them and the copper clip on the Tyler T attaches to the frame with the wood stocks holding it in place after they are reinstalled. At least that is my understanding...
The brass/copper "fins" on the t-grip are not meant to be bent around the frame. They just go between the grips and the frame and the friction holds them. DO NOT BEND THOSE TABS AROUND THE FRAME. Trust the friction hold. It works.
I'm a big fan of the T-Grip and have several. Since the 70's.
The Pachmayr grip adapter is similar, but I prefer the feel of the Tyler and the aluminum construction of the t-grip to the plastic of the Pachmayr. The Pachmayr is a bit thicker (from the backstrap forward) and without the finger grooves. I have to admit with some K-frame magnum snubbies the Pachmayr feels pretty good.