A lot of Walthams have a mechanism like that. It is a little sliding lever that actuates what they call the shipper. The lever sets into a narrow groove on the top side of the pillar-plate. I was unaware of the Hamilton using such a feature. Nice that you figured it out. Cheers.
I finally got around to getting the NH36 movement and changed out the day wheel. When I put on the dial and was turning the crown to establish the 12 o'clock position to install the hands, I noticed that no matter how much I turned the crown, it would not change over. Did I screw up something? I was turning clockwise like my other 7S26 Seiko.
The Spiedel wasn't really doing it for me, so I popped it on a plain leather band, somewhere between rosewood and burgundy.
Much more appropriate I think, and a sight more comfortable I might add. I was almost tempted to post it in "Watch of Today" again, since I'm still wearing it. Not a single issue so far, and hovering somewhere less than +20s/day aver the last couple of days.