I always de-burr all my shims and mark them with a Sharpe after I measure them. I use a sharpening stone to de-burr the ring and pinion gears and spool.
As Doug said keep all your bearings and gears together if you are changing gears. To me its worth it to just buy another spool and keep the side bearings with the gears and old spool together. There is a lot of us that do this without a spreader but I always wonder how much easier it would be with a spreader especially with a 40 pound Power-Lock unit instead of a 15 pound spool

Gus