The bogie axleboxes had significant wear on the front guide faces - as much as 1/4" missing on some.
This has been addressed by 'machining off' the old face and modifying the axleboxes to take bronze inserts, screwed to the machined face.
The photo above shows the prepared axlebox (lying front face down) with one of the new bronze inserts next to it.
The photo below shows the axlebox with the insert screwed into place, this returns the face to the original drawing dimension.
The modification should extend the life of the axleboxes indefinitely by providing renewable front guide faces.