Hi Pat theres a thread on the Axis History Forum on chinese artillery seems pretty diverse... most of whats currently produced for WW1 in plastic could probarbly be used... I did read there were only 800 guns available to chinese forces in 1940ish..

http://forum.axishistory.com/viewtopic.php?f=101&t=105386&sid=26adbc41f78fb5a7f075d54387f1660e

Japanese marines may have used a blue uniform...

http://www.ww2incolor.com/japan/C__pia+de+b+Shanghai+_13_.html

This blog seems like it could be usfull some good pics as well...scroll down for chinese with german equiptment

http://chinaburmaindiawwii.devhub.com/blog/category/china/page-2/


A Book "Shanghai under fire" (Shanghai evening post and mercury 1938) has many pictures of chinese soldiers including artillery MGs and mortars.... some pictures though are disturbing.

http://archive.org/details/cu31924023227824

Cheers