Here's a cost-effective way of making a custom steering column. Can be used as-is or cut down or extended or canibalised for it's component parts. Overall 460mm long with a 40mm collapsing/adjustment section. 48 x 3/4" spline on both forged steel UJ's. Rubber vibration damping section. The shaft is 210mm long and has a cross section like a house with a pitched roof (see picture). One end of the shaft is clamped to the lower, cast steel section of the vibration damper and secured with staked fixings.
COLLAPSIBLE STEERING COLUMN LINK #COLLNK2