I have to disagree with some of what Lee has posted. The 1980 Limitations Act gives the lender 12 years from the date of discovery of the debt (ie. the point at which the debt became known to the creditor- your lender). Although the lender would argue that this is the sale date of the property, a court would most likely accept a much earlier date such as the repossession.(posted 7991 days ago)Since you cite 1992 as the year in which this happened then sometime in 2004 you will no longer have to fear pursuit by the lender, DLC or anybody else. It will also become a criminal act to pursue you for the alleged shortfall debt beyond this date.
The DLC letter is clear evidence that they have nowhere else to go. Stay polite, keep requesting the information you need to assess the validity or otherwise of their claim and bat it out until close of play is my advice.