xj650 rear drum shoe size

So I purchased some new rear shoes from yambits (UK seller for most Yamaha bits) and these were labelled as 'fits xj650 81 onwards'

They arrived today but they are significantly bigger than the ones that I have in.

Am i correct in my understanding that the xj650 maxim (that's what I have) and the xj650 midnight have the same rear tyre and brake set up?

Ive found some shoes that will fix the midnight but it doesnt mention the maxim. The size of them is Y512 measure 180mm x 40mm -- is this the correct size for my 82 xj650 maxim?

 

I think my brakes were a bit shot...

 

the maxim shoe is narrower than the Seca or UK version
180 x 40 mm for 650 maxim

 

I followed the link you posted prior to your edit xj550H but couldn't understand it. I went out and measured the discarded brake shoes and got your above measurements

 

I went to emgo they do not list size then remembered I had a box from a set of shoes. Maxim has smaller diameter wheel in back

 

Well I appreciate the help, I've got some more shoes on order