Seidelmann did use Edson stuffing boxes as shown in Neal's link. The rudder shaft was 304, 2 1/2" Schedule 80 stainless pipe, tolerances on pipe for diameter and ovality are not very tight. Bearings tended to be fairly sloppy. Tides Marine can make much better bearings today than we used back then.
As I recall the stuffing box was epoxied into a pultruded fiberglass tube perhaps that bond failed?
304 stainless tends to be prone to crevice corrosion where water tends to be stagnant like in a rudder stuffing box, when you replace the packing look for pitting on the shaft.