Mick you have all the gear you need but two items mate.
Let you in on a secret of mine for years and years.
Best part mate is that the cost is about two tenths of F all.
No you dont have to wear womens undergarments.
Go check out your local op shops for bib and brace ski pants, the padded parker material ones work best. The other is the one piece ski suit same material. Midddle of Melb winter mate I ride around all day with jocks t-shirt one piece ski suit leather pants and dririder jacket. Warm and toasty, and even when you get soaked the stuff in the ski suit still keeps you warm.
I think my bib and brace cost me $15, and the one piece $25.
And because the material is silky it slides inside your leathers and jacket and does not bind up causing restristed movement.
also it does not bag up and therefor remains comfortable at all times.
My one piece siut even has one of those hoods, in Melb's worst I use it, helps keep the back of the neck dry and it does actually keep the head warmer.
Its only when the temp remains in single figures all day that I trade the jocks and t-shirt for thermals. For comfort and warmth I aint found nothing better.