gettinold - Nice group of stamps there. The price of these Shanghai China overprints definitely shoots up with better centering. Your set still looks good to my eyes.
Rod - Thanks for showing the reference work by Harvey Bounds illustrating the cancellations used on these stamps. Prior to this period, regular USA definitives were used in China and the duplex cancel used was different in the way the year date appeared. They only used a single digit for the year. Below is a piece I found in a stamp dealer's plastic tub of stamps for five cents each. The 7 in the cancel is for the year 1907. My second scan, snipped from eBay
, shows the same cancel with a 1907 Rumford Falls, Maine, USA (receiving) machine cancel applied, as proof it was 1907.
This is in my China collection, as a back-of-the-book item. I wish I had the entire cover, known a "red-band" cover for the red stripe down the middle. The whole cover would be priced at maybe the $40-$60 range, instead of 5 cents for the clipping. There is a lesson to be learned here, for all of you new to the hobby.