Ok, so I went down to Hong Kong island and the address mentioned above, only to find that the guy only opens Wednesday to Sunday and as CNY was coming up I didn't see much hope of that happening so I let it go. It is, after all, a very cheap watch from the 1970s and I can live with it. Plus, I managed to pick up an even better example of one of its close cousins on eBay a week later.
More worryingly, I've just managed to scratch up (a little bit) a new high end watch, so I might still go looking for a polisher after all.
BTW, what's up with eBay and not letting me sell a watch internationally until I've built up 10 seller rep points in Hong Kong? I don't think I've got anything the local market would want and I'm not sure so many locals use eBay anyway. Where do you guys go to shift high end watches?