The face is as stated by Atmasphere, bad filter cans can damage a power transformer. Unless someone has run the thing and determined the caps are ok, which is doubtful given the age of the Scott, I would never power up a unit like that unless you can monitor AC ripple and voltage while slowly running it up on a Variac. Normally, I just replace the caps and if that unit has a selenium rectifier, plan on replacing that too as they all too frequently leak voltage. No one should ever turn an old tube amp on without knowing how long it's been off and when it was serviced last. Finally, the twist lock caps in that unit should probably be replaced with current production single axial or radial caps. They can be installed underneath if there's room for them. That will make a big sonic improvement. The twist lock caps needn't be removed.