Tall 3 rung step ladders (Maldon CM9)

Aluminium (?) step ladders. Good condition & top quality. They have been well used by my Dad who was a painter & decorator for 40 years but they still have plenty of life in them. Total height open 40", folded 45". Height to top step 27", total width 16.5", height to middle step 18", each step is 12" x 8". For some reason I could not get the bottom step to open but I cant see why not.