Rear lights

I am looking at my rear lights after just buying new lenses from Superformance. The lenses are very average to say the least, but what I am really interested in in the sealing of the lenses to the body.

The plastic lenses have a rubber ring that fits on the lenese and locates on a couple of plastic lugs. What I need to know is is this the only sealing to the body?

My car has been painted at least 3 times and there are some remnants of some rubber stuck to the circulars holes where the lights fit into. It is hard to see if these are original or fitted during one of the repaints.

Any advice/information would be welcome.

Simon