34.zn Spanner dull zinc MMIE wide, Square nuts, ¼" a/f, cranked, square hole and ends, post-war stamping MMIE, underneath, flat angled end, 74 mm long, 5.70 mm across at crank, 1.54mm thick in a box of bits from a charity shop, yellow plates, zinc MMIE strips, slotted screws and a parboiled 194 black plastic flexible plate. The dull zinc has produced its own impervious oxide layer protecting itself and the underlying steel - the way zinc plate is supposed to behave. To work, the steel has to be cleaned with aggressive chemicals, and those need washing off before the plating. Much Meccano zinc is damaged by failure to clean properly and residual cleaning chemicals eating out from underneath the zinc