Specific instructions for three-way Turks Head
Can't speak to the Marlinspike Sailor (although I used to have that book somewhere...) but Brion Toss's book "The Riggers Apprentice" has detailed and specific instructions for tying this specific knot, along with detailed information on Turks Heads in general and why not just any turks head will work in that scenario.Anyway, highly recommended in general and has a detailed answer to this topic in specfic.