My 2001 SC45 has a full 45deg bracket with a pin driven in arount the same position as your one stops. I removed the pin to get the full movement so I expect it was a H&S measure. I am sure you could either order the newer bracket or get a machine shop to continue the slot. I cleaned my bearings which are the same as yours by disassembling them and applying some light machine oil before reasembling them. Never needed to touch them since and have been regularly using the machine for the last 6 years or so. The machine was designed for these bearings and cuts fantastically up to its full depth of cut. Blades used from 8mm to 20mm Rarely contact the side bearings but that might be down to the fact that this is a full industrial machine and substancially buit to fully tension the wider blades. Hope this helps
Nigel