The phrase "Aut numquam testes, aut perfice" is listed in Fairbairn's Book of Crests (1897- 1926 editions) as the family motto of the Ward family, untranslated. It is a one letter corruption of the more common Latin motto "Aut numquam teNtes, aut perfice". Literally "Either never attempt, or complete", more loosely - "If you do something, do it properly". I translate the one letter corruption as
"If you balls it up, balls it up thoroughly".
The 1933 edition of Fairbairn's no longer includes this motto!

Rod Ward
Aut numquam testes, aut perfice.