Ian,
I think you answered your own question in paragraph #2 above. The CPL is an L plate after which you are allowed to have others pay for furthering your experience. So not really applicable to you unless you want the piece of paper.
The theory side of it I'm sure you will find interesting- but all that and much more is freely available on the internet, or in book form if you wish. With your background it will be fairly simple- what you don't understand you can post here where you have a wealth of us "professional pilots" ready to tell you how much we know
There is no substitute for experience, as you said. But you can buy time with correct techniques until you have said experience. Alas not my words
but the words of an old PNG driver. It was part of our holy trinity up there. That, beer and... well beer
BUT, i digress, it seems like you have an itch for some more know-how so maybe you could find an instructor of a similar vintage to yourself who has practical experience. Pay him to go flying with you and streamline your operation.
Just a thought.
HJ
<check your PMs>