This is a particularly fine earlier Commando Observer's Half Wing as would have been sewn on to his 'Best Uniform'

Note the size here. The Badge is 112mm across at the widest point.
"Quartermaster's Comment":-  This item could date back to at least 1986 or earlier. It ran in different variants well into the 1990's. Colin Owen comes up with plenty of confusion. We have C 689 and 691 as well as C 695 and 696.