Hello Pete, that looks the muts nuts Have a look at this thread re lining pens ect PAD (Peter) used to be very active on here but sadly for us he has stopped posting his brilliant builds, You could try a PM though he'svery knowledgable about pens ect.
http://www.westernthunder.co.uk/index.php?threads/drawing-instrument-restoration.7195/
ATB
John.