1961 M69-1

One of the more obscure lines of Hamilton watches are the M-series.  There's also an F-series for ladies.  The M-series only showed up in the 1964 catalogs but they're believed to be made starting in 1961 and going into the mid 1960s.

If you didn't already know, you can find the catalogs on this page in my blog.  Check out the last page of the 1964 catalog to see the various M models.

The nomenclature used for the M series is the first number is the retail price of the watch.  The second number is the order the model came in that price.  So an M69-1 was the first model priced at $69.  1964 shows there was an M69-2 and an M69-3.  So the M69-1 was introduced before 1964.

One way to spot an M-series model is if it comes with it's original box.  The M-series (and F, as well) came in a red clamshell box.   The shape of the box is similar to the usual cream-colored Hamilton boxes but the color is red - so they're very easy to spot.  Here's a couple of example photos from eBay, right now.

Anyway, my belief is these models were distributed through a nationwide retailer.  Perhaps Sears, or Service Merchandise, or some other catalog-store that no longer exists.  Large enough to offer high end products that a quality jewelry store would offer.  I'm sure that Hamilton executives would be willing to offer a specialized product line that would not interfere or compete with their existing network of high end jewelry retailers.  That's just my opinion though, take it for what it's worth.

I've already done a post on the M69-1 but it's been a while and this one is actually a little different.  One thing is the same and that's that I received it without a crown.  This is a pretty common ailment of watches with a one-piece case.

The stem tube has a flat spot on it and I see no signs of the stem.  It'll be a two piece stem since this watch opens through the crystal.  So the crown side of the stem is probably still attached to the crown - wherever that is.

The case is interesting in that the lettering inside is a little crooked.  You don't see that very often, at least in my experience.  There are several service marks inside so this watch has been overhauled a few times before the crown disappeared.  The number inside is unique to this case but means very little to anyone but the Star Watch Case Co.  Presumably there's a P420106 or a P420108 out there somewhere.  My last M69-1 had the serial number P755427.  That doesn't imply there are 350,000 M69-1's out there though.  But there are likely at least two batches of cases for this model - assuming it's not shared with another Hamilton model.

This example has a 17 jewel 678 caliber inside rather than a 688.    The 678 preceded the 688 and they look very similar.  The main difference is the balance cock design and the balance.  You can see in the photo below that this balance has weights and a fixed hairspring stud on the balance cock.  When the 688 was introduced, it features a Glucydur balance and the hairspring stud was moveable.  That was a much improved design and made adjustments a breeze.

The female-side of the two piece stem is still present.  So all I need is the male side and a replacement crown.

From the dial-side of the main plate, this movement looks identical to the 688 movement.

If you didn't already know, you can tell this movement was made by ETA and it's based on a 2391 caliber.  So if you needed a part, any 2391 would serve as a donor, whether it was Hamilton or not.

Everything is cleaned and dried.  Time for it to be reassembled with fresh lubricants.

The sparkly movement is ticking away with a good motion.  Let's see what the timer thinks of it.

Not too shabby.  The beat error of 0.9ms is well within my specs but the hair spring stud is fixed on the balance cock so it would be very challenging to reduce it.  On a 688 it would be easy to fine tune but on a 678 I'll let sleeping dogs lie.

The male side of the stem is referred to as a "hub".  If you need to find one, look on eBay for a "Tap 10 male stem hub" and you'll see lots of examples.  The trick is to trim it to the proper length.  Tap 10 is the thread size for the crown.  If the crown was tap 8, you'd need a tap 8 stem hub.  After 1952 pretty much every Hamilton crown is tap 10.

The most common question I get from people is "what crown do I need for my watch?".  That's a very difficult question to answer.  Like the Supreme Court's definition of pornography, you know it when you see it.  In the case of a crown, there are so many factors.  For example, what thread size, is it water proof, how large is the stem tube, is there a gasket, does it recess into the case, how tall should it be, etc. etc. etc.?   

For this watch, I went with what looks best and fits best.

My finished project looks fantastic with a new crystal and a genuine lizard strap.  The crown is a perfect fit.  It looks like it just left the showroom floor.  All it needs is a red clamshell box.