Forensic teams.
The mere thought that the CT are asking for MONEY for forensic tests on these letters is abysmal...... What can they find ? Nothing. Nothing can come of forensic tests on decades old letters. The only point in the whole thing is to get more money.
and don't forget it's urgent. They need it within 28 days. 
You'd be surprised at what cold cases can throw up years later. Men have been released on " old information " being " found ".
CT will make nothing,they wouldn't be allowed to run the business as a profitable organisation which I'm sure they'll have gone into through Trudi's husband being a company director for a number of years.
Then again,there's a big difference in there being a slim chance or no chance at all to Wishing and Hoping that JB doesn't have a chance ! I rather feel it's the latter with most,sounds that way to me.