Have a cadet awards night.
A some point in the proceedings ( later on is better) someone has to give a pointed presentation to the assembled parents along the lines of,
A, Lovely to see the cadets doing so well and enjoying what they are doing.
B, Great staff, lovely building , latter if relevant, great opportunities for your cadets.
C, But, we are an excepted charity and under UK charity law are required to have charity trustees to raise and manage our funds. Our civilian committee are our trustees, and at present we only have two which is not enough.
D, Unless some of you come forward this evening to act as trustees then the squadron may be legally forced to close. ( So you loose your teenager babysitting service !!) .
That has worked for me in several squadrons I have been sent into with similar issues. But you must be BLUNT, no Mr Nice guy. Wear something distinctive, so that parents can find you afterwards, have a good handful of the CC sign up forms to hand, get those signed up on the night having talked through the legal requirements and checks that are undertaken on potential CC members.
Now I am unsure if the charity regs in Scotand are different to England but I doubt it,
In practise as a squadron chair I would talk to your wing chair first, but many squadron’s are in the same position as you currently and he/she only has one pair of hands, he/she may have a deputy or assistant he could send in but thats likely to be it. So its really in your hands to resolve, parents will only act if they think they will loose their teenager sitting service, they will attend an awards night but nothing else so thats the time to get them.
Its unlikely that you would get closed in practise especially with the charity changes that are coming down the track but the parents dont know that.
Let me know how it goes,