New 408 for the Flyfish

Years ago I worked in a repair shop/garage and “fixed” several motors with a spun bearing by sanding the crank down in the car.
You should be able to take a few thou of the converter snout the same way. Tear some emery cloth in strips the same width as the snout. Wrap it tightly around the snout, then wrap a piece of wire around the emery cloth 2-3 times around leaving like 2ft of wire on each side. Wrap the wire around each hand and saw back and forth. The emery cloth will spin tightly and sand the snout down evenly. Learned it from an old timer. On a crank you switch out to finer and finer until you reach .010 under. Takes time and patience. I’m sure the engine builders on here will eat this one up.
Good luck