NavList:

Thank you for that information Geoffrey.  I hadn’t considered all that.  I really just wanted to extend my ‘RIN young persons road show’ ‘Size of the Earth’ ‘Modelling the Solar System’ and ‘Directions’ etc. into ‘Triangulation’ and ‘Levels’, I’d not really considered looking into the sky with it.  I’d also quite like to try setting it up on or near my local trig point on the Lincoln Edge to see if I can see adjacent ones, although I understand that was usually done with lamps at night.  DaveP

This (I am sure) is a 'building site' theodolite​ and so the scales are marked in tenths of a degree or six minute intervals. This is not such an impediment as it sounds for celestial work, as it is easy to interpolate to the nearest minute.

What is an impediment to celestial work is the fact that it will (almost certainly) have no solar filter for taking sights of the sun, no right-angled viewer so you can take sights of Polaris (you cannot get your eye behind the telescope for altitudes greater than about 50 degrees), no means of illuminating the telescope cross hairs at night for taking sights of the stars and no means of illuminating the scales for reading the scales at night time.