Front Wheel O-ring and gasket on a 1976 GL1000

[DSA]

Hi,

Just had new tires installed on my 1976 GL1000. In re-assembling the wheels, I notice a couple of things:

1) The manual mentions an o-ring that goes around the hub, behind the disc on the right side (see attached pic). I can't see this anywhere on the wheel or the disc...though there is some residue that suggests that it was, at some point, indeed present. No idea if a PO forgot to reinstall, or if I lost it somehow while removing the wheels. It doesn't seem to appear in any fiche, so I can't find a part number for it.
2) The gasket (I think the manual mixed up the gasket and retainers in the pic attached) is broken.

I don't know how I am going to get a new o-ring without a part number, and I can't find anywhere online that has the gasket available. Am I good to just omit them and carry on? Seems like the risk might be getting rain or crud close to the bearings...but they do have internal seals.

Thanks in advance!

[DSA]

Oops, forgot to attach pic.