I opened up and cleaned an old Elna Supermatic a few weeks a go. The inner base of the machine were soaked with oil, thick layer of sticky goo as a result of previous over oiling. The gears were dry and grimy, very slow running and sticky machine until I had a couple of rounds with cleaning and oiling. So, yes, too much oil is not uncommon, and yet no oil in other places on the same machine. I hope you manage to sort out the motor.