American PW waltham model 1892 barrel arbor variations

[FredWJensen]

I have encountered an arbor variation on a Waltham Vanguard model 1892.
This is for a low serial number watch. One of the early Vanguards 21 jewel models. The arbor does not come in two pieces that unscrew but come in only one piece. The square key for the bottom of the barrel merely fits into the square in the bottom of the barrel. The tension in the barrel is held that way by the barrel bridge Has anyone encountered anything like this on a model 1892. By the way, I am having a problem winding the spring, perhaps I am not assembling it the right way. Please help.

I believe the part number for this type of arbor is
1628?

 

[FredWJensen]

Got it working.
This type of arbor just fits in place without screwing in.
Turned out the mainspring was broken too. I should have removed it first to check.
Then replace it with a mainspring from another waltham vanguard, and that spring was too wide, so that the barrel would not fit properly into the watch.....What the heck. I finally replace the spring with the proper size and the barrel works. But, I have a little sticking, before the power is transfered to the wheels? I left the pallet fork out to check the motion of the train.