I remember there being an article in Military Modelling 30 or so years ago that laid it out. But now to find that article again … I want to say that it’s called “That Tiger turret” but I’m not sure it actually is.
25 minutes later: I’ve looked at all the old MilMod issues I could find in the various places around the house where I keep them, and at the table of contents of those of the approximate era, but I haven’t found the article 
Either I must have some more issues somewhere, or I missed it. It did make me realise that maybe I should make room to have them all together, though, and sort them in chronological order.