The gears are sold in matched sets and are crazy expensive these days. I have changed individual gears with a good used gear, in pinch, with no bad consequence. M130 sedan gears are the same, but the vertical gear does not have the extension for a tach cable. I believe the tach extension can be removed from your old gear and possibly used on the sedan gear ?? There are early and later improved gears (see BBB) to identify. The horizontal gear in the block, you need, should be the same as more common fuel injected sedan gears of the era (w108 280se, 6CYL.)