Thanks for that.
By wading through the annual report for 2016 on page 96 and 97 I found as at 30 Jun 16:
AGOO Strike 7.5 Cents, Expiry 30 Jun 17, 1,744 million issued, 3,332 Holders
AGOOA Strike 7.5 Cents, Expiry 31 Jul 17, 4,513 million issued, 60 Holders
So I was wrong in thinking AGOO expire 31 Jul - its actually 30 Jun.
So in theory AGOOA are a better buy - but going by the depth don't seem to have the liquidity?