Got it - thanks Jeff.

If it's not obvious, then I'm just going to have to take it to an experienced transmission mech. According the parts view - they could have come from anywhere.

 

I had a look at the 6 speed diagram at lunch. The smaller ones look like synchro key retainer *****, part number 17-341J on the drawing, like the ones I've seen in Getrag trannys. The larger ones I'm not sure. Either way your are going to need a teardown to figure out what happened.