MLU FORUM - Bagnold sun compass

I am currently in the process of making a replica Bagnold sun compass to complement a Cole sun compass we have.
With help from Kunho Gross and some information from the IWM, I am making progress. However, dimensions I am missing are the outside dimension of the worm that rotates the shadow disk and the diameter of the shaft that drives it. I have already made the disk and some of the components below it.
I have contacted the various groups that are interested in the LRDG but have had no replies so I assume they are dormant.
Can anybody help me either with the dimensions or the contact details of anyone who may be able to help me please?
Alastair
F60S