I had a similar experience. Got solicitor to write to Mart (Co-op) and have name changed on share register. I'm not sure that these shares have much value as in my case the shares bought at the start at one pound each in the 1960's. I believe many Co-ops continued and may still continue to issue new shares in subsequent years at equal value. Can anyone advise on this?
Depends on the mart and what assets they hold. It is likely that if the mart share was valuable your father would have known and would have mentioned it, however you should certainly pursue it. The mart will value the share although they do tend to put a nominal value on shares except in the event of there being plans afoot and member approval to sell assets.
If this is the only asset to be dealt with certainly Id suggest writing to obtain a valuation first as it may not be necessary to have a solicitor involved. If a solicitor is already or about to be engaged in relation to other assets they could also deal with this. The only thing I would say is to be aware that some marts have rules about who can own shares and the transfer may need approval. I know of a case where a wife wished to transfer her share to her husband and the mart refused to approve the transfer.