I harvested this out of the bay for about $50. It is a redial so that is not good but the price was right for a watch that I really wanted for the movement.
This is a Favre-Leuba 17 jeweled winder from what I assume to be the later 1960s. The interest is the Calibre 253 movement that Faver-Leuba made themselves. It is one of the few twin barrels (two mainsprings) movements. Longines made one. I assume others did too but have not yet encountered them.
The above picture shows the two barrels.
By having two mainsprings, a watch is more resistant to changes in time keeping due to changing spring tension due to state of wind... or so the literature reads. It may also allow a longer power reserve for the amount of space devoted to mainspringing ... but I know of no studies existent which would shed light on either conjecture. Maybe others do.
Not a bad buy for $50... but it is in bad need of a service so the cost will probably soon triple. (Watchmaker is backlogged and is only getting 'priority' watches nowadays.)