I just picked up a nasty (dirty) looking Kenwood Model Eleven at a garage sale for $3. I was trying to remove the face plate to clean it but it appears that the tuning knob is held on with two allen type (hex) screws. I have an allen wrench set but none fit it. Does anyone know if these are metric? I suppose they might be since they were made in Japan. May have to make a run to the Tool store but wanted to make sure before I buy a metric set. Thanks.