djwillis, As an answer to your comparison of RTMO to RTMCA I can...

djwillis,
As an answer to your comparison of RTMO to RTMCA I can see a difference: RTMO are free carried until November 2009 (10c option). Where as with RTMCA (7c with 1c paid so far) holders could be billed 2c per share any day now as per the conditions:

"The Company shall not make any call in respect of the unpaid capital owing on the Contributing Shares until 15 March 2004. Thereafter the Company may make calls on the unpaid capital owing on the Contributing Shares, provided that the amount of any call shall not, when added together with the amount or amounts of all calls within the previous 12 months, exceed $0.02 per Contributing Share."