JD bearing is slightly smaller than rollerblock bearing, and the tolerances are lower, no mirror polished surfaces etc. Darumas look like Aurios cookie with two halves, but only a single bearing is used.
If you go to add in tweak section, member DK405 has link to
site with pictures of darumas.
If you go to add in tweak section, member DK405 has link to
site with pictures of darumas.