There was mention of different ways to use a fret saw when cutting dove tails, but they can be used for so much more, so here is a new thread on fret saws.
My description of the Great Neck 250 was incorrect, it does not have a washer for the serrations, the clamp threads into the handle. There are serrations on the bow and the clamp to allow swinging the bow 360°. The two saws on the right are both marked PEER. The one all the way to the right says Germany and the other says West Germany. This probably dates one to pre WWII and the other to after WWII.
The one all the way to the left has no markings. It doesn't have a top fine tensioner. It does have some sort of decorative "finial" or such. My only thought as to use is to catch it on something while setting the blade tension.
The second picture is a detail of the Great Neck's mount to the handle.
jim