Advice sought on GNR wagon axleboxes

[MikeWilliams]

I want to make a pattern for a GNR 10-ton oil axlebox, as used on very many open wagons and covered vans. Please does anyone have a large scale drawing of the box?

My models are in Gauge 3 (2 1/2in gauge), so it needs to be a decent drawing, or a decent couple of pictures with some accurate measurements.

I must confess to being fairly ignorant of GNR matters, so would welcome advice on exactly the right type of box - don't want to spend a long time making an obscure non-standard type. I have already made the common grease box, so want the oil type with a handle at one side.

Thanks,

Mike