The next problem is how to remove the crown and thence the movement when the setting lever pin is located to the rear of the movement.Closer inspection of the channel around the dial adjacent to the crown reveals a helpfully dimpled tab.It seemed to me at the time that pretty much every watch worthy of consideration was fitted with some variant of the Seiko 61 or 62 series movement, with the lesser fare served by a movement caliber beginning with a 7.The honorable exception to the rule was the Bell-Matic with its innovative 4005/6.It is easy to develop a misapprehension, when first dipping one’s toe into the pool of what a particular watch company’s vintage back catalogue has to offer, that every watch is fitted with one or other minor variation of the same movement calibre.I plead guilty to forming just such an impression during my formative years as a vintage Seiko obsessive.At 28.6 mm diameter, the 830 calibre was a little wider than the 603 fitted to the first Seikomatic released a few years earlier, but at 3.8 mm thick it was a full 1 mm thinner than the 603.
Once we’ve got to this point, we can flip the movement over and survey it from the rear, a view not offered until now because of the absence of a removable case back.
With the hands removed, the dial comes next, once the recessed screws gripping the dial feet have been loosened.
The view provided of the calendar side yields no surprises; a conventional layout not dissimilar to that used on the 62 series.
The C variant of the 8305 followed a few months later, now also featuring a hand winding facility.
All variations of this movement were highly jeweled, every one of which serving a purpose.