@James & @Symptoms - the oldest map I can find with the Top End Mechanics Institute named is an 1896 map, National Library of Scotland, and it shows the building named at what us now the community centre. The 'Old Maps' site has now moved, taken over by 'Landmark Estate Agency Services' and you can't access the maps unless you join. So the only maps I use now are from the National Library of Scotland.
Don't know if @Canny lass has access to other maps.