From memory on my 2003 1300 there is some differences between the front and rear.
I think that the rear should have a extra slit in the backing plate which works as a key way when fitting. I think that I had to modify the last set that I purchased off the E Bay, Supposed to fit but would not , So used the trusty angle grinder to cut out the little key way slot as required . I suggest when you pull the pads do a comparison check between the front and rear of the old sets of pads.
The memory also tells me that something was too thick to fit in also , so I only replaced one side and then reused one of the least worn old pads for the other side , also I left out the stainless backing pad in order to get the extra clearance required.
I do not do a big mileage and I have a brake pad inspection down on the must do maintenance list which is due in a couple of months , just in order to keep an eye on things.
Hope that this helps,
Chers, Winston66