(a) inscribed in fibre-tipped pen on support reverse u.l.: Mt. ZERO / (L.H.S. FRAME) (b) inscribed in fibre-tipped pen on support reverse u.c.: Mt. ZERO / (CENTRAL FRAME) inscribed in fibre-tipped pen on support reverse l.r.: JOHN ONEIL / 83 (c) inscribed in fibre-tipped pen on accompanying support reverse u.r.: Mt. ZERO / (R.H.S. FRAME)