After being unobtainable for a while due to Shapeways changing their minds about what will print I've got round to fixing the Hudson axleboxes for Gn15 I do http://shpws.me/IA1L - They have increaed slightly in price but I still think are good value at 50 cents each !
We had some discussions on here about whether they were too small - will I took a recent opportunity to take a picture of one with a tape measure on a 15 inch gauge truck.
I reckon it's 116 mm wide so 4.8 mm in 1:24
Mine are 4.5 mm wide - very slightly too narrow, but I don't think anyone will notice.
I'll try and sort out some other axleboxes too in this scale.