Rear drum

I've only just purchased my 650SS so I'm trying to sort out the little issues it has, one of the major ones is just how oval the rear brake feels. I've taken the drum off today but I can't hold it well enough to check how far out it is.... so is this a common problem to have a warped drum? It doesn't look that old so I'm wondering if its a cheap foreign part?

Hello that well maybe there make them in India , ebay its where there sold,

what your chain size early 650SS had 3/8x1/4 chain up to 1964,

Your pic doesn't help to identify the chain/sprocket size. A pic of the teeth with a ruler next to them will show - as will actually measuring the width/thickness of the teeth.

You should take it to a machine shop first and they will tell you if it is fixable. This used to be a common fix on cars when they used drum brakes.