Guest, if you google 'buy used guitar advice' you will find tips on what to check on a used instrument.

My own thought is that a guitar from the mid-60's is 45 years old. Where has it been all those years? It could have been left in a garage, a basement, or a hot car. Such environments damage an instrument. It could have been dropped on its head. How much do you trust the sellers?

Meanwhile, you can get a new Martin tenor from Amazon for $449. (That's just one example.)

If you do, be sure to use the Amazon link where the Mudcat gets a cut.