Withe backing of an insolvency plan, certain shareholdings' values can be retrieved:

General shareholder information - Capita Share Portal
https://www.babcock-shares.com/forms/FAQTopic.aspx?SectionID...
How much are my shares worth? You can check the number of shares you have,
and get an indication of what they're worth online using the Share Portal.
Cached
Claiming money or property from a dissolved company - GOV.UK
https://www.gov.uk/claiming-money-or-property-from-dissolved...
You may be able to apply for a court order to restore a company if: ... Apply to the
Court of Session if initial value of the company's shares that have been paid for ...
Cached
About your shareholding - Rolls-Royce
http://www.rolls-royce.com/investors/share_information/faqs/...
Why do I have two different shareholder reference numbers (SRNs)? ... What is
the “nominal value” of a Rolls-Royce share? .... certificate and once a share
certificate has been reported as lost it cannot be reinstated if it is subsequently
found.
Cached

An insolvency plan can help to reclaim shareholder value

"In this letter, we lay out our thoughts on how the board can reclaim shareholder value by refocusing the Company."
Read more: http://www.businessinsider.com/paul-singer-elliott-managemen...