[...] visiting the Monville tunnel by moonlight.

So, this tunnel?

You should add this to the event page! so people can sign up

We will be adding letterboxes to this years event and are in need of some
people to help out with the Letterboxing side of things.

oo that works!

My Dear, if you list your event on the Events Page of this web site, with or without a complete name, you will find letterboxers signing up to attend. From there, you will be able to ask them directly and specifically for assistance, whether you need stamp carvers, or help with planting and writing clues, or just general planning. There are people in your general area who have a great deal of experience with this sort of thing and would be a wonderful resource for your event. Naturally, you can edit your listing later once the full name has been determined, and add other clarifiying details whenever you wish.

Aunt Agatha