Handlebar Removal

Hi everyone Good morning,afternoon, evening whenever you are reading this post. I am trying to remove the handle bars from my 1919 Skootamota to replace the ball bearings.. I have removed the long bolt down the middle and the steering bearing tension collar ring halfway down the steering column so that the column falls out of the headstock,hopefully all balls collected, but I cannot remove the handlebars to allow the column to be removed from the headstock. Does the handle bars just knock off the column or is there an additional device still holding it? I suspect it is just the accumulation of rust and paint holding it but would like clarification before I knock seven bells out of it.
Many thanks in advance
Emlyn
 

Have you loosened this bold on the top of the handlebars and tapped it down to free the wedge that holds the handlebars? http://suprememotos.com/uploads/postfotos/1920-abc-skootamota-125cc-good-runner-v5c-rare-vintage-scooter-9.JPG.

The downtube is held by a wedge that expands a split cylinder in standard bicycle fashion.

This is a picture of the arrangement
https://www.mopedarmy.com/forums/file.php?6,file=185850

Greetings, Emlyn, and Welcome to the Skootamota Free Advice Clinic.
To enlarge on Roger's input, the lower end of your central bolt engages a tapered plug. Tightening the bolt pulls the plug up into the (split) lower end of the Handle Bar Tube, expanding it into the Steering Head Tube, and thus gripping it.
What you have to do, is reinsert the bolt into its plug, and whack its head with a lead or copper mallet, to dislodge the tapered plug. (Refit the top threaded ring of the Steering Head Tube to support it, before the whack!)
After that, twisting the 'Bars should overcome any rust or other binding medium, to loosen them.
Good luck!   

Thanks Roger, Paul. I now know how the column comes apart, unfortunately the threads on the end of the center long bolt has most of the threads rusted off, so when I wacked it with my Hide hammer it when straight through the threads on the cone. So I am now going to make a slightly longer bolt to try and knock the Taper out. Can anyone tell me what the thread is on the bolt? It looks to me like a 5/16" BSF thread. Not enough thread to put a thread gauge on.
I have only got 5/8th of an original skootamota. IE 10x2.5" wheels, internal brakes and a automatic engine fitted. (I do have the original engine for this machine)  it is fully legal for road use and have been out on it. I have decided to refurb all the rough bits. Wheels are being done at the moment. Brakes I will use until correct ones come along.
Anyway thanks again all for the help.
Emlyn
 

Emlyn,
I suspect that the thread will not be BSF as the fittings will be bicycle ones with a British cycle thread which are usually 26 tpi. Why bother to thread a rod as you are trying to knock the wedge and can rethread once it is released it if it is damaged?
Regards,
Roger