This Fender Twin Reverb has come up for sale for $800. Recent model Twin Reverbs in decent condition go in the region for around $1000-$1200. I don't know the year but the seller thinks it is a 1972-1974 model that has had some upgrades / repairs over the years. The seller believes the reverb box was replaced, and believes the speakers were replaced with Celestion G12 Vintage 30 8 ohm speakers. Issues are - cosmetically, it's in rough shape. I would be inlined to replace the tolex and speaker cloth. The tubes look new - they were likely replaced. Clean channel sounds fine. The vibrato channels have a click. So - buy it or pass on it? What's involved in this repair and does anyone know the fix? Here is the sound of the click.