Though this a Magnum the brackets and linkage are 1968. The extension for the throttle pressure linkage is a piece of 1/4" brass pipe. The threaded ends were cut off. Then it was threaded internally to match the threads of the linkage. The original rod was shortened slightly. Then the adaper was threaded into the front portion with a 1/2" long piece of a cut off bolt. Drilled one hole for the spring so it tucks under the carb to the rear. Made a slight extension for the cable as well.
That plating/coating on your throttle bracket sure looks nice.
What is it?