The Tonbo Brief https://tonbomarket.com/briefs/ Midweek dispatches on the JDM watch market. en-us Fri, 12 Jun 2026 06:30:02 GMT Tonbo Brief . 6-10 . 62MAS pricing looks broken https://tonbomarket.com/briefs/6 https://tonbomarket.com/briefs/6 Wed, 10 Jun 2026 00:00:00 GMT Two 62MAS listings. One question. The Seiko 6217-8000 is the original First Diver. Made between 1965 and 1968. It's the watch the 62MAS collectors argue about, the one that commands serious money when it shows up in good shape, and the one that almost never surfaces twice in the same week at buyout... Tonbo Brief · 6-3 · When the data misfires https://tonbomarket.com/briefs/5 https://tonbomarket.com/briefs/5 Wed, 03 Jun 2026 00:00:00 GMT The listing that looks like a steal. And isn't Three deals topped this week's margin scan. Two of them are the same seller, same product category, posted twice with slightly different SKUs. The third has a 89% margin flag on a 1960s dive watch listed at ¥15,800. Numbers like that get attention.... Tonbo Brief · 5-27 · Grand Seiko straps hiding in plain sight https://tonbomarket.com/briefs/3 https://tonbomarket.com/briefs/3 Tue, 26 May 2026 00:00:00 GMT The accessory arbitrage nobody talks about Most flippers chase the watch. The strap is an afterthought. But this week's data surfaced something worth paying attention to: genuine Grand Seiko leather straps, new old stock, listed on Yahoo Shopping at prices that make the math look broken. It's not... Tonbo Brief · 5-20 · Vintage Lord Matic spreads https://tonbomarket.com/briefs/2 https://tonbomarket.com/briefs/2 Wed, 20 May 2026 00:00:00 GMT The mid-tier vintage floor just moved Three Lord Matics closed this week with gross spreads above $85. All under $115 landed. That's the kind of margin you used to see only on mint SARB pieces or popular Alpinists. Vintage Seiko inventory is behaving differently than modern discontinued models... Tonbo Brief · 5-13 · The 6309 margin puzzle https://tonbomarket.com/briefs/1 https://tonbomarket.com/briefs/1 Wed, 13 May 2026 00:00:00 GMT The vintage diver nobody's watching You know the Seiko 6309. Mid-70s to mid-80s diver. Came before the 7S26 generation. Usually listed between ¥15,000 and ¥35,000 depending on condition. Solid tool watch. Nothing glamorous. Yesterday a 6309-8580 closed at ¥22,800 on Mercari. Fair market median...