A couple of months ago when we flew out to the NAWCC Del Mar Regional Watch Show I bought several watches, parts and orphan movements.
I finally got around to taking a close look at one of the orphan movements that I bought at the show over this past weekend.
I found it in a bin full of movements and cherry picked it.
Now, when I bought it I thought that it was an open faced model 1900 Waltham size 0s movement with 15 jewels.
But, I tried to put it into a size 0s case it would NOT fit.
I double checked the case size that I was trying to put it in, the case was in fact a size 0s.
I decided to take a measurement of the movement and it measured 29.97mm.
I then zeroed out the digital micrometer no less than five times and every time it measured 29.97mm.
It is .35mm larger than a size 0s Waltham movement which is 29.62mm.
I then searched through my bins for a size 1 Waltham movement to do a comparison.
The size 1 Waltham movement is 30.48mm so it's NOT a size 1.
This movement is in-between a Waltham size 0s and size 1.
Another VERY strange feature is that there is NO Waltham stamps on this movement.
There should be a "WALTHAM" stamp on the train bridge but there isn't, the movement is blank.
It does have an eight digit serial number that reads "10176509" in the EXACT same place where an open faced Waltham size 0s should be.
But, if you run this serial number through one of the online databases it states that this is a size 10s, grade 1015, 15 jewels, model 1900.
I thought that the database had an error which happens sometimes so I broke out my Waltham serial number book written by Ehrhardt back in 1976 and the same information is given, a size 10s (page 68).
Now, anybody who has ever worked on these early Waltham movements from the turn of the century will see that this is in fact a Waltham made movement.
The movement design and layout is VERY recognizable as being an OF Waltham, model 1900.
One other thing has me scratching my head on this one, there is an extra screw on the barrel bridge and I have NO IDEA what it actually does.
I cannot see it serving any purpose, I haven't ever seen this extra screw on any other Waltham movement.
Look at the picture that has the tooth pick pointing to this extra screw for a good look at what I am talking about.
When I bought the movement it did NOT have a dial or hands on it.
I decided to check the dial feet locations on the pillar plate and they are in the EXACT same location as a Waltham size 0s movement model 1900 or 1907.
As you can clearly see from the "side view" picture a size 0s Waltham dial fits perfectly.
When I took the movement apart all of the serial number stamps are matching, 10176509.
This serial number can found in no less than five places on the movement parts.
So, what is with this movement having NO Waltham stamping, a blank un-stamped train bridge, the extra barrel bridge screw, size 0s dial feet locations but the pillar plate diameter is in-between a size 0s and a size 1s movement?
Can't say that I have ever seen anything like this one.
I would love to read your thoughts, hopefully somebody can shed some light on this one.
Looking forward to your replies!