WElcome to the forum Dane,,, nice to have you with us.....
If you have an Accushot/Leapers 1 piece scope mount then don't even worry about using a "scope stop" or even the scope stop pin in the mount,,,,, you won't need it if you install the mount properly.
First thing you do is clean ALL surfaces with denatured alcohol. Clean the top of the guns receiver and clean the dovetails slots cut into the receiver until they are squeeky clean.
Next, using the alcohol clean the scope tube..... where the mount will clamp over the tube (this removes any grease etc. and prevent slippage)
Next, use the same denatured alcohol and clean EVERY surface of the 1 piece mount including taking the allen screws out and cleaning them and their threads. Once that is done you can now mount the scope as you would normally, however use the BLUE loctite on all mounting screws as you install the mount. There is RED loctite and Blue,,,, the package will clearly state which one it is.... or you can just ask the guy who works in the hardware store, he'll know what you need. Tighten all screws tight then put the rifle away for 24 -48 hours for the loctite to dry and cure.
After the 24-48 hour waiting period take a sharp pencil and use it to mark the position of the scope rings on the scope and the position of the scope base on the receiver. Just run the pencil around the outside edges of the scope rings thus marking the scope tube and do the same on the receiver where the mounts clamps on. This will enable you to instantly tell if the scope mount or scope have moved at all. But trust me, if you follow these procedure nothing will move.....
Next...........go shoot your rifle and have fun... the scope should not move one bit.
Let us know how you make out.....
BTW.... that TF-89 is one powerful, nice rifle. I have one in .22 caliber and it's one of my most powerful springers. A great hunting gun
Jeff