Doug Mason has produced several excellent scholarly studies and many of them deal specifically with WTS chronology. He has generously contributed many of these articles to this site (ad1914.com) Doug Mason also maintains his own site at jwstudies.com where he continues to post new work and updated versions of previous works. You will find some several of them on his site that we have not posted on this site. of his work there that we have not posted on this site.
The following study is 40 pages, well-organized, well-documented, and well-illustrated.