Looking to replace the axle sealing rings 901 331 283 00 on my 66' 911. Currently on my car are 2 different types of seals. One looks like it could have been the original (right one in the pic below) and the other is an o-ring. It is part# 16 in the diagram below.These are no longer available. Any suggestions? Thanks

<img src='https://i.imgur.com/j4KEeVx.jpg' />

<img src='https://i.imgur.com/ZnVa9HN.jpg' />