Thanks for the additional info and pictures. My part looks like the one G posted

And the width of the hub, from inner stop (for the bearing) to inner stop is 77.5mm, so basically the same width as the spacer, with a little crush room.
Doug@8000'

Bearings arrived and fixed all the issues. The brake caliper shows some slight sings of "rubbing", apparently due to the wheel assy being too far back in the fork because of the wrong bearings. Back on the road (once the snow melts). Thanks to all for everything! Doug@8000'

and the bearing spacers went well with the new bearings meaning they only do touch the inner race ?

G.

G,
Yes, spacer worked fine. The new problem occurred while loading it on the trailer to take it home....finicky bitch! Check my new post, I need a turn signal switch lever. Thanks for all teh help with the bearing issues.
Doug@8K'

20 mm axles were on some SS models, and they came with white wheels. I agree that the wheel probably just got changed some time in its life. All other aspects of the wheel were the same. You might find a mfg. date on the wheel, and that would tell you directly.

The Ducati / Brembo wheels are rather soft, and dent easily, which may have been the reason for it being changed. On the plus side, the are easy to straighten, from a straightening service. I have had several wheels straightened for about $110-125 USD and they came back beautiful, and did not disrupt the paint at all. Maybe I bought your old wheels and had them straightened.

I think you need to order a new internal spacer, or take the one you have to a local shop and have them duplicate it, but with a smaller ID. The spacer is nothing special, except for the length. Use steel, not aluminum. The ID should be a bit more than 17mm as you don't want the axle fitting tight to it.

Cheers,