Hi guys, I was fishing at local antique shop, the and the owner come up with this Polerouter SS case with black dial, black dial is patinated and it appear very dark red in natural light (hard to spot on camera) Ofcause, I tried open the case back with my tools, but it loses grip, so i give up after a few time, as i don't wanna risk scratching it. So until now, I have no idea how the movement look like. I did shake it and hand feel the movement of the rotor, and indeed it's the feeling of micro-rotor. (I do own another polerouter 218-2, so i know) So judging base on the shape of the case, I bet on the movement should be okay, I hope. I need your help on identify the reference number of this watch, as the reference number engraved on the case has a large scratch, it wiped out certain part of the reference number, it shows 20xxxxx on the upper line (I guess it's a 20357?), and 19248XX at the lower line which i assume it's the serial number and please can you assess the shape of the case and dial from your POV? EDIT: Is the crown original to this reference? Does the dial look "Tropical" to you? Thank you.