I've read that even lot of the ford mechs didn't know about them until they started snapping - the Haynes manual you have is the last paper manual they did ..they have moved on to downloads.
Haynes were very good once, but they lost the plot, maybe late 80's, around the time they started adding the 5 spanners easy / hard thing .
I think that manual was mostly compiled with pictures from stuff they had for other fords that shared the engine,.
Anyway you don't need it ...only useful for specs and toque settings , hopeless for rear drums ..as does not have clear diagram showing brake shoe assembly ..these can go together many different ways ..you'll find out.
ALAN HOWATT ON YOUTUBE is the best man to show you how to do things on these engines
https://www.youtube.com/watch?v=-l6-JUImJQw&t=1247s
He's far better than any Haynes manual.
there is an American ford OE Paper manual on the connect - very rare to see in the uk ..not sure if it covers all the things we need as in the USA, petrol and auto boxes were the thing. of theses manual -- there are 2, one for the electrics and one for everything else - 400 pages plus
all the best..mark