New Zealand postage stamp, issued in 1950, SG 700, Scott #273
"When standard letter rates increased to 1˝d in July 1950, it was realised that stocks of the 1938 King George VI stamp would be inadequate. An urgent order was placed for another printing from England, but to fill the gap until stocks arrived a provisional stamp overprinted on the 1931 Arms Postal Fiscals design was issued."
http://stampsnz.com/1950_arms_provisional.html