Hi Bob:
If you can disassemble the hubs, I have used WD40 (very little amount) to lub other hubs with good results.
Yes, the Darklab hubs with metal flanges are compatible with Otari B3 but not B2.
Although most of the after market plastic hubs would work, I found some of them from eBay to be not as good as the original Revox hubs. It seems its hardness is not the same and after while the spring loaded spinlde can work itself into the base with the hubs from eBay- still works but different... The metal flanges are mostly machined and anodized the same way as the original Studer flanges. They look and function identically to the original Revox. However, the Darklab kind from Jeff would have the name engraved into the metal flanges.
There were several earlier posts regarding the sources for the Otari parts. I do remember Otari stocking the side panels. I have had a local cabinet maker make me five sets of side panels for B2s. He did a very good job but it wasn't cheap...