Rebreaking to drive ?

When i brought my first pony, 9 years ago, we were told he was a 'ride and drive' pony and saw some photo evidence etc. and up till now he has only been ridden by us, but as he is getting older (21 years old now, but still very lively!) i find less people able to ride him as he needs lighter riders, yet is... show more When i brought my first pony, 9 years ago, we were told he was a 'ride and drive' pony and saw some photo evidence etc. and up till now he has only been ridden by us, but as he is getting older (21 years old now, but still very lively!) i find less people able to ride him as he needs lighter riders, yet is quite a cheeky pony - too much for a unconfident child. I also am dying for a horsey project this summer, so i was thinking of re-breaking him to drive. No extreme work or anything, it would just be nice to take him out on the cart every few weeks to keep him going.

I have a little experience, as i used to help drive donkeys when i was younger and saw some of there breaking techniques - long reining, sledging a panel of wood, introducing to the cart and then just getting on with it in a way! - they also used desensitising techniques like making them walk over plastic, road signs, with plastic on them, yet i don't think my pony needs that as he has done loads of little handy ponies and obstacle courses over the years and is very calm, as if he has already had these techniques done before. But i would be working with my friends Mother who has broke two ponies to drive, as i don't have enough of an idea myself.

So basically...

Do you think it would be possible to re-break him?
Is it fair on him being an 11.2hh Welsh Mountain pony at 21 years old to be driving at all?
Any tips?!

Thankyou! x
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