Further to the topic 13 posts down on the Shinhoto Chi-Ha turrets by Tamiya and Fine Molds, as well as available drawings, I asked Taki by e-mail.
This is his answer:
See the drawing in my site.
The turret of Tamiya' kit is too small.
PS: the original link goes to Taki's site, page on the Shinhoto Chi-Ha ("drawing"):