Westerly Conway cutlass bearing

[Yoya]

Hi all,
Trying to find out the dimensions of the prop shaft cutlass bearing.
I will need to order the part before I start the job.
The shaft is 30mm diameter and so should be the ID of the bearing but what is the ID of stern tube, which should be the OD of the bearing.
Has anyone replaced the cutlass bearing on a Westerly Conway ketch 1979?
The ID of the stuffing box is 42mm but I doubt it is identical to the stern tube ID.
Many thanks