Capital gains on shares

[sole]

We (my wife and I) were given some shares about 1970. They are in a UK company (Imperial Tobacco)
We sold recently for about €10 000.
For the last 12 years we reinvested the dividend each year in shares(about 10 shares pa) .
We have no idea how to calculate capital gains. We see some mention that rate for overseas companies shares may be 40%.
How could we possibly work out the original cost.
And it is more complicated by the company being taken over by Hanson at some stage and shared with some other companies and taken back by Imp.

 

[jpd]

If the shares were a gift or inheritance, then the value would have been the value (number of shares x price ) at the time. The company secretary should be able to give information on the share price.

You will have to try and get a record of shares splits, bonus issues, etc to arrive at the number of shares that were sold for € 10,000

The initial cost can be indexed up to take account of inflation.

If a broker held the shares, then they should have historic information.