Seiko Mini-Tuna 7C43-6020
Here’s another rare bird: the Seiko 7C43-6020 a.k.a. Mini-Tuna.
I bought this watch with the shroud missing. I took the watch to an official Seiko dealer in Brussels who had it shipped to Seiko BeNeLux and after about a 2 month wait, they came up with a replacement!
Very nice watch (and actually not that small) with a domed chrystal. I actually found the shroud made it pretty hard to move the bezel. Don’t know if this model was ever available outside Japan (I have yet to see another one for sale since I found mine) and so it had the Kenji day/date wheel.
These are part of Seiko’s Quartz ‘Professional’ series, rated to 200m.
Twilightdivewatches 
pretty sweet. i’m on the verge of getting mine. It seems as yours was made in 1992. Pretty awesome!