Email received 100 years later - Douglas Mawson - Explorer.

We received an email from a gentlemen requiring information about an
old theodolite.
Ironically, we received this email on the day being the 100th year
anniversary of the explorer Sir Douglas Mawson in Antartica.
Can you help!

"Dear Global Surveyors,

I have a Brush & Mac Donnell (Melbourne) theodolite in its original
leather covered carry box, lightweight tripod, Günter's chain, Ice
stand and Plumb bob.
I believe it was used by Sir Douglas Mawson at the South pole on one
of his expeditions.
It was acquired some 35 years ago from an Adelaide based institution
that Mawson was associated with.
How can I find out some more information regarding this interesting
piece of equipment?
I would be very interested in its value, both economically and historically.

Another ironic thing is that the instrument was stored in an old shed
in the Adelaide hills for over 25 years.
The road name which the shed was located on is the same as Sir
Douglas's surname. Mawson Rd. Adelaide Hills"

Regards, Dave E -
Adelaide.

Please respond in the comments section below.