Waltham Traveler Ser.19,211,147 (c.1913): The watch winds smoothly, ticks beautifully, but I cannot pull out the crown to set the time! I apply up to around 4 lbs force at various crown positions, but there seems to be no available "slot" for pulling out the stem.

What could be the problem here?
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I don't know a lot about Waltham's but is it possible a lever set ?

This is my fourth Waltham Traveler of the same period, and I can assure you, all are stem set. Also, the setting is done by pulling the crown outwards, not pushing inwards.
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Check for rusted or broken sleeve jamming the stem,
could be tough though to get the movement out to check.
Good luck.

Steve

First, does the crown "pop" up to set position? If it does and then it will not set, remove the movement from the case and try setting it with a bench key. Out of the case it should stay in "set" unless you push in on the bench key.

If it sets Ok, that usually indicates the collet needs adjustment in the case neck.

If it does not set OK, then you have to dig deeper into the Crown wind and set mechanism.

This is fairly simple. To check it out requires removing the hand, dial, and then lifting the motor bridge. Inspect the mechanism and check for free in-out "snap" of the wind set mechanism.

Unless the clutch spring is broken, there must be something that is not lubed.

Dave and Steve,

To detail the behavior even more, the crown will not "pop" out at all. It will move slightly inwards when pushed and then spring back out. The crown rotates normally and winds smoothly, but the slightest movement outwards is not possible.
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Paul

Sounds like the stem is catched and blocked by the sleeve in the winding position.

First check John D. Duvals tutorial:

Stem and Sleeve Assembly

Regards
Gerald

Paul, I had a crown stuck like that and my watchmaker used a nipper pliers as shown below and was able to pull it right out. It didn't take that much force but it was more than I could apply with my fingers.
He had modified the jaws by rounding the cutting edges so they wouldn't scratch anything. I made one for myself and have used it on a couple difficult cases.
Of course the safest way, if you can get the movement out, is to unscrew the crown and use a sleeve wrench to take out the sleeve and stem to see exactly what the problem is.

Dave, it does kind of remind me of the dentist I had when I was a kid. No Novocaine and a drill that turned about 40 rpm. And he had a few tools that looked like this one.