Rick,
If you want quick and easy you can put an 1128 into the B-mann pocket and use the spring from the B-mann knuckle coupler. This will work but the coupler can move up and down a fair amount in the B-mann plastic pocket. The best answer is to use an 1133 plastic pocket with the MT metal insert and an 1128 coupler. Getting the 1133 plastic pocket into the clips where the removed B-mann plastic pocket was is a tight fit, you may have to file a bit, but once it is in it is staying. MT claims the 1133 is the replacement coupler, but the coupler height is a little off if you use the 1133. The 1128 is perfect.
