I have several W&G machines but none have the on/off switch. As far as value I don't think simply bypassing the switch internally such that the bypass can be removed later would effect the value. Of course, fixing the switch would be best, buy that is not always possible. These are wonderful machines and deserve to be used rather than just sitting on a shelf looking cute and interesting. If bypassing the switch is the only to get it going again I would go ahead. We are not talking about ruining a $15,000 antique. The bypass could not ruin the value by more than a couple hundred dollars at most and if it is the only way to make it usable there is an argument that would make it more valuable since a working machine is always worth more than a nonworking machine.