I've been to all the centers in the GZ watch district and there isnt much to find other than your average canal street stuff. They have cleaned up alot as the local govt is starting to regulate the industry. I would recommend emailing/contacting a dealer beforehand, otherwise you wont find anything unless you speak Mandarin.
As for the watch district, there are 4-5 main centers. They are all structured like a indoor swapmeet but each individual booth is an "Independent Watch Broker".
This is the main intersection. If you head left, it'll lead you to the subway (1/4 mile) and the EMS center (the one that all the GZ dealers use LOL). The building behind me to the right (which isn't in the picture) is where I found most of my tools (up the stairs, immediate right, end of row) I think I still have my receipt if you need the booth #. They sell rep Bergeon tools and are pretty inexpensive. I walked out with pretty much everything I needed for less than $20usd. Just to the right of the picture is a pretty decent sized center to find more crap. On the upper left corner where you see the big clock on the building is another center. I think it's about 4-5 stories...I didnt venture up all of it because of all the cigarette smoke throughout the levels...and smoking is legal everywhere. There is also a side street there (the no right turn sign). That's a whole other street with more crap.....
More crap with lots of crap. This is the famous center that an old school member had posted in his review.
Another view of the street:
Inside the centers:
Outside another watch center along the main street:
If you are looking for accessories, you will find everything possible on the main st (first picture). Just walk another 1/4 down and that's where all the rep glasses, purses, jeans, shirt, underwear, hats, shoes!!, etc are. I spent 2 days in the district and didnt even get to see everything. I hope this gives you a 3D/live view of the intersection. Have fun!!
cc