OK....for the seal you pictured, it was foam and the end caps still visible were part of it. What I did for mine (non-column shift steering wheel) was to replace the foam with a closed cell foam sold as camper seal weather strip (cut to the correct width) and glue to the shaft between the still captive rings.
Now....what I was thinking of was the actual smaller steering shaft seal that usually disintegrates and people don't realize one was there. Attached are pictures of that seal w/captive end rings. This seal is like the larger one in your picture, but smaller.
Mike