About the multiple gears, do many setups use the 60's and the 55's? If
they were used in almost every common setup, it would make sense that
Myford might anticipate unusual wear and include a spare of those gears
likely to wear down fastest. Besides, those gears sound like some of
the largest in the set. Large gears have more teeth, so the
probability that a tooth will become broken or damaged is higher than
on a small gear.