Here's an example of a Neilsen that I recently overhauled.
As received, it's in pretty nice shape. It has a glass crystal with some small scratches. I'll have to purchase a replacement, as you can't buff out scratches from glass.
The dial is a little dirty but not too bad. I forget for they call the green funk that you often find on gold filled cases but it is definitely going to have to go.
The back of the movement shows off the nicely damascened details. I really like the 747 movement - it's a clean, straightforward, classic design.
The back of the dial is unmarked - the scratches around the perimeter are from the riveting process for the 18K applied numeral. This has all the indications of an original dial.
A nice fresh white alloy mainspring with a little grease will give this watch about 40 hours of life on a full wind. I still need to put the cover on the mainspring barrel though - but this view shows you the spring and arbor that will wind it.
Next in is the escape wheel which engages the pallet fork and the fourth wheel. The portion of the fourth wheel that is down in this picture (ie not showing) is the second hand bit that the second hand attaches to.
The thing I like about the 747 is the wheels are very easy to line up so the train bridge can be reinstalled.
Everything but the balance is back on. So now I give the crown a few turns to make sure the mainspring engages and generates power through the gear train. If the pallet fork was not installed all the wheels would simply spin until the power was released.
The balance on this particular movement was probably replaced, as this type of wheel I think was made later on. The original probably suffered a mishap and a complete balance assembly was installed in it's place. The little red spot is the impulse jewel. It engages the pallet fork as the balance swings back and forth, each swing moves the pallet fork and allows the wheels to turn one increment... 5 times a second.
With the watch now running and ticking away, it goes onto the watch timer.
9 seconds fast per day, that's pretty good. A slight tweak to the regulator to lengthen the hairspring ever-so-slightly will slow it down.
And here is the completed reassembly, ready for a strap and a new glass crystal.
I happened upon a Neilsen that came with it's original inner and outer box as well as bracelet... sweet!