Morris minor traveler 1968/9

[Rousell]

Hi Folks, I have a 'new to me ' Morris traveler now, and I notice a slight dip on the passenger rear side. From the back one can see a slightly lower position , than on the driver side . I have noticed this before on other other travelers I've seen a rallies / shows etc . The spirit level shows about an inch lower. Are there are common causes of this such as leaf suspension fault ?