[codefox1]

If you took the bells off you could just as easily put heat shrink tubing over each wire. Try to use the same color as the original. The idea is to prevent short circuits or arcing. If the set is playing normally and the transformer does not get too hot (you should be able to touch it after it has been running for an hour without becoming burned,) you do not need to replace it. The hum is another matter, re check your work, especially polarity of electrlytics, measure voltages, etc... you'll find the problem.