Update to where I'am at with the Simplex.
I have now found out it isn't a Thrustmatic, rather band type gearbox.
Had the engine in electrolosis for a few days to try and clear the rust.
Worked out Ok.
Then soaked as much as I could with ATF and acetone mix to free up the components.
Finaly got it broken down into pieces, but have now put away to finish other projects first.
Some pictures attached.