Body to rear bumper seal questions

[JimKshortstep4x4]

My son's 72 Burb did not have a seal between the rear bumper and the body but the Assembly Manual shows one.

Does anyone have a seal on their Burb? If not is there a dirt problem on the back from water splashing up?

We are thinking about making one out of rubber, (I made one for my 69 El Camino and it works very well). If anyone has made one, how did you fasten it to the body? (The manual shows that it it screwed on but our Burb does not have holes).

Any comments would be appreciated.

Jim