Small office chair (Mill End WD3)

Black fabric seat (40cm wide x 38cm deep) & black plastic back (36cm wide, 34cm from seat to top of back, 85cm from floor to top of back), 5 shiny chrome legs (approx. 55cm dia.). Lost its lever to adjust height. Slight mark on seat. Seat stuck at it's current height of 54cm from floor, when sat on this reduces to 52cm.