Yes Bilal Gunj would have what you are looking for like Storm says.
However you need a post 68 pedal. 67 and earlier pedals were different and would not be compatible with your car.
The price you are going to pay depends on the mood of the scrap dealer. Expect anything from 150 Rs upwards.
A while ago brand new Brazil made accerator pedals were seen in Karachi. Not sure if the shop still has them. If memeory serves right they were something like 600 Rs without the rubber cover. Good quality and powdercoated by the manufacturer.
Best regards.