I can echo the comments.
Used fabco series 23 also.
Had to compress the pins with vice grips and pounded them in.
I doubt they will ever fall off.
As to digging, WOW! I was able to pry out rocks too big to fit my FEL bucket in mt driveway.
Matter of fact they were heavy enough to create the 'pucker syndrome' when the rear kinda left the ground.
I resorted to push/roll them aside.
Being spring thaw I wanted to get rid of the pesty frost heaved imbedded rocks.
The soil is a clay based subsoil that is hard as concrete when dry. In the present wet condition they came out easily, but otherwise it would have required a full sized backhoe at least.
Also tried some old stumps in the 6" variety. Piece of cake.
Loading full buckets of soil with imbedded stones was awsome.
Without teeth the cutting edge would simply deflect off of even a 4" stone rendering a bucketfull near impossible.
Now I get full loads every time.