Pete, from your description I'm not sure what to say.
Here's the obvious:
1) '67 was first year for safety collapsable steering column. Underneath a plastic sheath there is an expanded metal collapsable portion.
2) Floor shift column would obviously not have a spot for a column shifter, nor should there be shifter forks at the base.
Most importantly: if you bought it out of a '67 Chevelle, what makes you question whether it is out of a '67 Chevelle?
Thomas