There was an Open Day several years ago that I went to. They probably hold an open day every year.
I travel through Melton Mowbray several times a year, and some of the pastures for the horses are alongside the road. The Horses always look well groomed and smart.
If you write them a letter, I suggest the address : Officer Commanding,
Defence Animal Centre,
Melton Mowbray, Liecestershire will find them.