For intangible assets,we cant take FMV as on 1/4/1981
We have to take
COA=actual costs (purchase price) in case these assets are acquired
COA-0, in case Cost of acquisition
For more details.
pls refer
http://teachoo.com/800/81/Capital-Gain-in-case-of-Intangible-Assets/author/teachoo/category/Special-Cases