Parking brake lever rubber boot

Could just be a slightly modified part - they tended to add letter suffixes for bits they’d tweaked - or could just be another colour moulding.

 

But whatever it is, it's listed for post 72 buses.

 

Better than chopping a perfectly good floormat up!

 

Perhaps the A version is the small piece of foam or plastic as seem above! It's doing the same job?

 

Mebbe. At least the mystery's solved...