SEIKO 1719-3020 Rare, Case-back Crown, Kameido, Manual Wind, Unstable Operation

Thank you for looking.

I am offering a very rare, hand-wound SEIKO wristwatch for sale.
*Please note that the operation is unstable.*

I have been searching for a well-maintained example of this model for many years, and I have finally found one that satisfies me. Therefore, I am offering this one for sale.

While this particular watch is in very good external condition, the only point I was not entirely satisfied with was that one of the black caps on the columnar lugs (top, bottom, left, and right) is missing.
Other than that, there are some minor scratches, but I believe the overall condition is quite good.

This is a hand-wound dress watch with a unique rear crown, manufactured by Kamedo Daini Seikosha.
It seems that watches of this design were released in white and black, each in two sizes. This is the larger black model. The lug width is 18mm, making it a stylish choice for men.
I feel it may have been designed with reference to the size of Cartier's Tank watch.

I have worn it with NATO straps and leather straps.

When I wound it up for listing, it was working, but it has since become unstable, stopping intermittently or losing accuracy.
Please consider this watch with the understanding that it may require servicing.

Size:
Vertical: 32.5mm
Horizontal: 25.5mm
Lug width: 18mm

I believe it would also look great on women. Thank you for your consideration.