I'm afraid they don't do you any good, nappybaglady! If you're going Virgin, Air Canada, Singapore, and Air New Zealand, you need the UK, Canada, Singapore, and New Zealand rules. In the UK it's up to the airline. They may allow carseats for infants over 6 months, but may make up their own rules as to which ones. The Canadian rules look a lot like the US ones:
the Canadian regulations just says it has to be labelled, basically, and
\lint{http://www.tc.gc.ca/CivilAviation/commerce/circulars/AC0177.htm\the clarification}
only clarifies that for US ones (which have to say they're approved for aviation use) and Canadian ones (which are all OK).
The New Zealand regulations say (part 91.207)
(d) Paragraphs (a)(1), (2), and (3) do not apply to a child under 4 years of age if the child? (1) is held by an adult who is occupying a seat or berth, and the child is secured by a safety belt attached to the adult?s safety belt; or (2) occupies a seat equipped with a child restraint system, if the child does not exceed the specified weight limit for that system and is accompanied by a parent, guardian, or by an attendant designated by the child?s parent or guardian to attend to the safety of the child during the flight.
So theoretically they could let you use any old child restraint system. (The exception bit just means the baby doesn't have
to be in an adult seat with an adult seat belt).
You're on your own with the rules for Singapore...