Prusa Y carriage linear bearing holder

The Y-carriage on the Prusa i3 has space for 3 linear bearings. They're attached these days with u-shaped metal bolts that are good and sturdy, but have two caveats: 1) they're only available from Prusa or the long-boat from China (copies), and 2) You run the risk of over tightening and deforming the bearing.

As I was putting together a new Y carriage, using Drylin RJ4JP bearings, the deformation was especially a concern (plastic bearings deform easier than the metal housing). Also, I didn