eileen mason , 92 , knocked would-be thief to the ground with her scooter .
mrs mason and friend margaret seabrook , 75 , were attacked in swindon .
` evil looking man ' tried to steal contents of their scooters ' baskets .
the great-grandmother-of-13 , accelerated , and rammed the attacker .
after he was knocked to the ground , they sped off on their scooters .