yeah it was alway emi but an oversight meant it was never written on the label, later labels then had the EMI box added so emi weren't missing out on any advertising. Also The harvest company bags always had an EMI box on even on the non-emi boxed singles.
No , always an imprint of The Gramophone Company , Ltd ( one of the subsidiaries of EMI ). EMI went through a time of adding the little box logo to all their record brands at about the same time ( Columbia for example ).
From Wiki ( The A-Z of record Labels.(Brian Southall) (2000). Sanctuary Publishing. ISBN 1-86074-281-5.) : Harvest Records was created by EMI in 1969 to market progressive rock music and to compete with Philips' Vertigo and Decca's Deram labels, initially under the direction of Malcolm Jones and Norman Smith.