If you are up to the challenge and have steady hands along with good eyes, you might be able to save your original coil. In a single cylinder motor, the secondary winding is composed of wire thinner than a human hair and one end is attached to ground while the other end is connected to short length of braided wire which in turn has a small terminal on it which the spark plug wire fastens to. If your alternate firing motor has only one coil, each end of the secondary winding is connected to the two terminals on the outside of the coil, no ground connection. On this style coil, the ohm reading is taken across the two terminals to determine the condition of the secondary windings.
If one of the terminals is broken off, you might be able to carefully remove some of the coils outer jacket and find the end of the braided wire. The broken terminal can then be soldered back on and the coil sealed with a clear epoxy. You have to be careful here so you don’t damage the fine wire winding which is just under the jacket.
These photos will give you an idea of what is inside and how fine the wire is.
