(Please revise this. The details are confusing and sometimes contradictory.)

There were four Wicker Men, says Shaffer. (Hardy says three: two full and "one down to the thighs"... - Wicker Man Enigma documentary.) The head, one used to take shots from inside of it, and the two on-site. One was called "Hero.", a film term ("Hero" props are the more detailed pieces intended for close inspection by the camera or audience." - Wikipedia) It was 15 feet off the ground. A shorter version was three feet off the ground. Another was 36 feet off the ground (and also called hero...). Brown also mentions a 60' man... The Aylett man/illlustration below was used as a basis. Flannery brought enough wicker for two men with heads and one spare head. (Brown) Three heads were assembled. (Brown)

The men were constructed out of wicker “hurdles” which were what were used to make fences with. "Pyre wood" (long telephone pole-like logs) covered the legs. The "Hero" (#2 here) had wooden slats added around the legs which are on a raised base covered with hay. 

The original wicker man was built by the O'Doherty family (aka Keeley Hire/Keeley Hire (Film and Television) Ltd, -  Heidi Wilson, Facebook Wicker Man page, 5/20/14. John Sexton's father helped build it, probably at "the farm in Ponsbourne Park (Hertfordshire ) or if not in nearby Wormley West End where O'Dohertys was based." (FB Wicker Man group, 2018

#1 - full, 70 (36 ft?, concrete base?)

#2 - used for closeups (Howie yelling to the islanders and saying his final prayer), had a concrete base, stumps sawed off awhile ago. This was the one used for the famous last scene where the burning head falls and we see the sunset. (Shot by the second unit.) (Pics of the site can be seen #1, #2, #3,#4.) 15 feet off the ground? "C 1972" written in the concrete base. It is about 100 yards south of the tallest version. (Also described at being built 500 yards away...)

#3 three feet off the ground?, just a head?

Plus a trial Wicker Man? built, not at Burrowhead, but at a secret location near to it next to a body of water. (This could be the Hero man.) This is mentioned in Alan Brown's book and confirmed by a press photograph showing an almost fully constructed Wicker Man surrounded by scaffolding (up to it's head) standing by, and reflected in, a large calm expanse of water (also described as being on "low ground close to water.") The Wicker Man appears to be on a grassy area and is presumably close to the bank of a lake or large pond. Legs cemented into the ground, says Brown. (The Galloway Gazette mentions one but doesn't say where it was.)

The "trial" Wicker Man:
Test WM

Plus a wicker man "jr" who went to the Cannes Film Festival. This was an unused structure. It was placed in front of the Carlton Hotel on the Promenade de la Croisette. Roger Corman noticed it and became interested in the movie. it was burned there.

WM at Cannes

The drawings by either Seamus Flannery or Robin Hardy used to design what we see in the movie.

A popular image of a Wicker Man, the "Aylett man."

Wm old

Cutcloy Farm supplied straw to help with the burning.

Billy Lyons Sr was head of the fire brigade used to keep the fire under control. He is interviewed in the BBC short Country Tracks (2009).