Drop in Share Value to reduce CGT liability

I hope this is the right forum for my query.

I will have a large enough CGT liability this year and I believe I had a shareholding a number of years back that dropped in value for which I could offset my losses. Unfortunately, I have no paperwork.
Back in around the year 2000 to 2005 I was part of a management team in a company that was gifted shares by the parent company. They held a highly value at the time but the company subsequently went downhill and bust. The company was called Scoot.com

Can anybody let me know how I would go about tracing the share register for this company to track my own details.
I would also like some feedback on what level of information I would need to use this to offset my CGT liability.
Any push in the right direction would be greatly appreciated.

You can make a negligible value claim - check it out on the Revenue website. Do you have any share certificates or anything like that? If you were allotted shares personally (as opposed to a nominee account) and it is an Irish company then it may be on the CRO website and can be downloaded (a Form B5 is used for allotments). If it is a UK company you may be able to find something on the Companies House website.

Did you pay for your shares or did you pay you pay income tax (perhaps through PAYE) on the value of the shares? Unless you incurred cost (either directly or through income tax) I think you will find it very hard to get a tax deduction.