AAAAH!! The Wren.
Mate of mine has a lovely Wren 182 (they have their own Type Certificate, as I recall, more than just a bolt -or glue on mod.) and he has even screwed a few more horses in the front by way of an IO-550 -- what a seriously fun aeroplane to fly.
As for the whole discussion, there is what you "can do", what is wise to do.
If it all goes wrong, it will be between you, your god, your insurance company, and CASA's rather variable (depending on their desired "policy" outcome) application of CAR 138.
Bloggsie,
Your interpretation of the venerable US Naval publication and how to fly an approach in larger turbine aircraft (but it works for any aircraft) certainly explains a lot??
Tootle pip!!