Tientsin 1903 Shandong Cover – Postal History

The cover shown was posted in Tunchang, Shantung on 28th day, 7th month, "ping wu" (1906) to Tientsin. There are transit marks of Linching, Shantung (29th day, 7th month) , ????, Chilhi (1st day, 8th month) and two Tientsin marks. One (a) from Tientsin 1 shows the date 2nd day, 8th month (day as the character "jih") and with the "ping wu" lunar characters for the year. (b) shows the day as the character "chu" and 32nd year. This 32 signifies the 32nd year of Kwangshu (the emperor) and this designation is only recorded from Peking and Tientsin (Chang, chapter 24).

It is interesting to see that the only date shown by Chang for Peking is 11th day, 10th month, 31st year, whilst Tientsin is recorded between 18th day 7th month and xxth day 9th month, 32nd year. My cover falls in the middle of this date range. Can anyone extend these dates? The vast majority of those recorded were used as arrival marks, as here. Were they ever used as cancels?