Fitting replacement
As service letter mentions those fittings are on the prop already,(3b) it’s the 106545that is mentions will replace them on the non grease side.
That is completed at prop overhaul, I assume by a shop. Call Hartzell or a prop shop if you want that fitting, would be my guess.
I’ve had no issues with my fittings the last 9 years of relubing them.