Hi Narayan , This link may be of interest in terms of making a Unity Finder.
http://www.gcw.org.uk/1xsight/finder.htm .
There are details for constructing the 'Ezekiel Unity Finder' ( Rigel like device ) on P 306 - 309 of Phil Harrington's 'Star Ware' , 3 rd edition published by Wiley. Hope this helps
