Mustang 332 no spark

[Mustang 332]

Good afternoon, I was gifted a Mustang 332 by my brother when he passed. Have an Owatonna service manual from Jensales, but not much help, I am mechanically inclined, but at 70, I have forgotten to much. Lol It ran when I got it, last winter it started running on 1 cylinder and when I went to start it this winter it would not start. It has fresh gas and I can smell gas after I try to start it, so I am pretty sure it's getting gas. The plugs are new. When I started looking at it It did not seem to have spark, their was an accell aftermarket coil on it, yellow, looked like for a motorcycle, took it to a small engine shop and they said it had very week spark, ordered a correct coil, still would not start, turns over very well, fully charged battery. I am second guessing myself on the wiring of the coil. There are 2 wires together coming from the switch, I believe and 1 wire going to a skinny electrical box on the back of the engine. Now the old square /funky coil was held in place by tie straps and had no markings on the connections, the new coil, which will now fit in the original mount has a + and a - on the connection points, I take it that the 2 wires together, coming from the switch, I'm thinking, would be connected to the + and the one wire going to the little box on the engine, facing the front but not sure. Tried it both ways w/no success. I am going to by some new wires, points came w/the coil, distributer cap/rotor and whatever you guys think I should replace. When you open up the back door, it is an Onan 25 hp gas engine, are the distributor and such under the yellow cover on the back of the engine, I really don't see them around the engine and the service manual doesn't help. Thanks in advance, sure would be nice to get it going, will snow soon in WI. Mark