Ok
So my original Cutlass column ended up being no good as it had previously ben cut and welded (god knows why). I managed to get a couple more broken shafts from my importer and after some design speak with a hydraulic/steering company we come up with this solution.
Video showing the outcome
The attached pics show the shaft fully removed and exploded then the spring mechanism that stops rattle between the two pieces and how it all goes back together.
In this fashion the column can still collapse and is now truly serviceable