I work for a large life & pensions company, and according to a colleague here, Abbey Life have been closed to new business since 1997. The cheque should never have been sent direct to your ex-wife anyway.
As has been said previously you will be best speaking to an IFA. You can search for an IFA at
www.sofa.org or send me a PM & I could put you in touch with IFAs I know in the Leeds area.