I am in the process of rebuilding my series 3 suffix A gearbox and I assume I need to replace the 1st /2nd gear Synchroniser part number 608283. The inner ring (no idea what else to call it) has several wedges broken off next to the channel where the small plate / ball bearing / spring thingys are located - at two locations on both sides.

My questions are as follows
1 Am I correct in assuming it needs to be replaced (in other respects it appears to be in good condition and the motion of the inner ring appears unaffected)
2 Where to look for a decent quality replacement - most suppliers appear to be out of stock including synchro gearboxes who have supplied me with all other replacement parts and the rebuild kit.