Scrap yard or tip etc.
Dont need many tools.
Anything with easy start or 'electronic' on the engine cover. Or anything sprint.
Tip the mower on its fuel side and look for the wires going to the points compartment in over the top of the valve chest. If theres none, put the plug out, test for spark and pull it too bits.
For me, ive got coils here but an offer of $20 or even $30 is not worth my time to bother with getting the money from you and going to the trouble of posting it. Its worth more to me, in the 3.5hp engine bits box just sittin there ready for me to lay my hands on it when you need it.
The fact that most of the mowers i get from the scrap yard are minus the starter, coil and primer carb tells me that you need to hit it hard and regular to get what you want. Well your mate does.