Coil looks like it has seen better days, so take it off the laminate by cutting thru one side with hack saw, place assembly in vise and driving the laminate out of coil.
Next step measure the laminate pole the coil was on and look for a cheap coil that will fit with or without trial and error fitting, It may seem a bit CRUDE, but, adapting a currently available coil beats looking for something that may ve HARD to find. IF you are VERY lucky you may find a used coil at a small engine shop (used) for a nominal sum. Be aware that small engines went to solid state systems about same time as outboards. Coil needs to fit into the available space , fit on the laminate and a high voltage output that can be routed thru the magneto plate without interference with anything such as flywheel. cam or points.
I am probably the least qualigied to advise on magnetos. There are those wo REALLY know the subject on this site They may have specific suggestions to address situation.
Louis
