Thanks, Rodney and Cari! Those are great suggestions!

Never use Duct Tape for electrical insulation. Use UL rated, electrical tape. It comes in colors as well as black, if that matters. DH is an electrician and he says well applied electrical tape is safe until you are able to rewire the machine. Just be sure to wrap each side separately, or you will blow a fuse or trip a breaker.
Then wrap over the 2 sides. It won't shock you or start a fire if you do it right. We have done that to cotton wrapped wiring and rubber rapped, but we ALWAYS replace it. The rubber just keeps coming off in new places. It will allow you to try the motor and see if the job is worth the cost to repair.

Sometimes, the old controllers are just plain worn out. DH checks them and finds the contacts that the finger moves over are worn and not making good contact. The Nichrome wire breaks and the old controllers get too hot sometime. We prefer to replace them with the with the solid state controllers from Sew-Classic.com for under $20. They are on sale for just under $17 right now. IT IS THE BEST MONEY I EVER SPENT. Intend to get one for all my old machines. I have one on the FW and it saves a lot of carrying weight. They are much lighter. After using one, there is just no excuse for the heavy, Ceramic type with old time technology. You can save them, if a purist wants to put it back someday, but to use, you can't beat the solid state type. My back and shoulder don't have to tote the heavy things around anymore.

I forgot to mention that we rewire all our machines, as a safety matter. It costs little, unless you need gromets and strain relief. If you do a lot of machines, you can get a roll of the correct gauge wire for your machine. Some applications require a soldering iron for the connectors on some controllers. Never use acid core solder, only rosin core for electrical applications. Practice is everything. Instruction is really needed to get a good end result. Some applications use, flux, a chemical, to make a prettier result. I'm sure U tube has something on it.

Sometimes, the old controllers are just plain worn out. DH checks them and finds the contacts that the finger moves over are worn and not making good contact. The Nichrome wire breaks and the old controllers get too hot sometime. We prefer to replace them with the with the solid state controllers from Sew-Classic.com for under $20. They are on sale for just under $17 right now. IT IS THE BEST MONEY I EVER SPENT. Intend to get one for all my old machines. I have one on the FW and it saves a lot of carrying weight. They are much lighter. After using one, there is just no excuse for the heavy, Ceramic type with old time technology. You can save them, if a purist wants to put it back someday, but to use, you can't beat the solid state type. My back and shoulder don't have to tote the heavy things around anymore.

If I were to buy the one on sale for my 301, do I just attach it at the foot control end using the existing cords? I dislike the button type controller on the machine now. The wiring is in good shape on both machines.

I learned just last month from watching a bunch of youtube videos and practicing. Lots of practicing. You can get a set of clip things called Helping Hands? that holds the wires for you. Its not hard.

my son taught me how to solder, it is easy. scary at first. a little practice and .... WALAAA you did it.

Yes. You disconnect the two wires going into the button controller by loosening the screws, and hook those two wires into the new controller the same way(or follow the directions that come with the new controller). It doesn't matter which wire goes to which connection. Personally, I like the button controllers when they're working properly.

Cari

If I had normal feet, the button would be okay, but I have as many plates and long screws as bones, it seems. Not very flexible. Thank you for the answer. I didn't want it to be the machine end.

The button works fine for a certain little dog. Both dogs needed under my feet during the never ending fireworks. Moira, the little Border Collie mix, laid on the controller. I had to move my hand quickly, then move her. No sewing during fireworks!