Seiko Willard: the 6105-8110 vs the SPB151 and SLA033

	6105-8110 (1970)	SPB153 (2020)	SLA033 (2019)
Diameter	44 mm without the crown guard	42.7 mm	45.0 mm
Lug to lug and thickness	48 mm, 12.5 mm	46.6 mm, 13.2 mm	49.7 mm, 13.0 mm
Lug width	19 mm	20 mm	19 mm
Movement	6105B automatic, 17 jewels, 21,600 vph	6R35 automatic, 24 jewels, 21,600 vph, about 70 hours	8L35 automatic, 26 jewels, 28,800 vph, about 50 hours
Hacking and hand-winding	Hacks; no hand-winding	Both	Both
Water resistance	150 m when new	200 m	200 m
Crystal	Dual-curved Hardlex	Curved sapphire	Dual-curved sapphire
In Seiko USA’s catalog, Oct 2026	Not applicable	No	No

The original’s dimensions are Seiko’s own measurements, given to webChronos. The SPB153 figures are from Seiko UK’s product page. Seiko’s pages for the SPB151, the bracelet version, are gone, so we haven’t confirmed its figures separately. The SLA033 figures are from Seiko’s 2019 release and its UK product page.

The SPB153 is the compact option: 42.7 mm and 46.6 mm lug to lug against the original’s 44 mm and 48 mm. The SLA033 went the other way, slightly larger than the original at 45 mm, with the same 19 mm lugs. All three use the asymmetric 1970 case shape.

We’ll add the original 6105-8110’s sold range after our first sampling of eBay sales in November 2026. The modern watches no longer have a current Seiko USA price. We’ll sample them separately and won’t mix them into the original’s range.

It’s the watch from 1970, with the 6105B movement and the turn-and-lock crown, and its Apocalypse Now history. The risks are the usual ones for a 6105: replaced dials, hands and bezel inserts, rebuilt movements, and crown seals that may be 50 years old. Read our 6105-8110 buying checks before you pay, and treat it as not water-resistant until it’s been tested.

The SPB151 and SPB153 give you the shape with a 200 m rating, a sapphire crystal and a movement that hacks, hand-winds and runs about three days. They’re the more practical everyday watch, and a used one has far fewer unknowns than a 50-year-old diver.

Seiko kept using the 1970 case after the SPB151. Its later versions include the SPB237 (2021), the SPB257 and SLA061 Black Series (2022), the SPB301 Save the Ocean (2022), and the SLA069 Naomi Uemura edition (2023, 500 pieces), which was still in Seiko’s global catalog but not its US one in October 2026.