The Sinn 240 State-of-the-Tide complication, obvs. Must get one of these.

I second that.

Ebay UK, but the dealer/refurbisher is based in India and sent the watch from there. Estimated delivery time was about six weeks, but it actually arrived in about ten days.

Here's a link to another from the same seller: https://www.ebay.co.uk/itm/353911158282?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=DB8X9F49TSi&sssrc=2349624&ssuid=W_9RZNMDSGm&var=&widget_ver=artemis&media=COPY

I have an itch for high accuracy quartz, and the 43mm lunar pilot just might scratch it. 

Very nice. The Nato is an excellent match, both in colour (it looks very grey green on my phone) and in style - a leather strap would perhaps not work so well with the modernist feel of the watch.

Ooh, at least show us the modded Royale!

Got this one refurbished from an Ebay bay dealer in India. About £25 with postage. I'll put it on a shiny black lizard or croc strap and keep it for the dressiest occasions. I think the proportions are actually more pleasing than the luxury brand tanks, and I utterly loathe cabochons on crowns, so my enjoyment of this watch is out of all proportion to its cost.

If anyone's interested, he seems to have plenty more, with a variety of dial and case colours. Just search 'Seiko Tank' and you should find them