Strange Letter from Barclays

Could you try a different branch if you dont hear back?

I popped (well made the journey) into Barclays who confirmed the number was genuine, but said they couldn't (wouldn't) help me and I was just to keep ringing the number.
Well, I'm not prepared to keep my phone tied up all day long waiting for them to deign to answer, so I've written to them asking THEM to phone ME.
Still waiting for a reply, I wonder if I'll get one.
I'm glad I'm not still in a state of abject grief, they were not at all helpful.

I'd go to your nearest Barclays branch and speak/explain to someone.

DH had a letter from an insurance company stating that they had funds that were due to be paid to him. Turns out it was a policy bought by his father when he was born, to be paid out on his 60th birthday. They took a year to track us down and we had to supply lots of evidence and identity.
His father had died 18 years before all this, and it was quite emotional. (Not a great amount though )

don't ring the number given on the letter.
look up barclays and ring number given or send email.

I agree with cornergran take the letter into a Barclays branch to get it checked out before you go any further. If there isn't a branch near you scan or copy the letter and send to Barclays.

Probably, she had a long term investment/bond which you and your brother were not aware of. But 14 years after her death ? While we're on the subject, how do next of kin find out what investments/accounts their deceased relative had, unless they were privy to it it. ? (I mean, If there was no Will)

If there's a branch near to you I think I'd go in and show them the letter. Alternatively try to find a customer service number for Barclays investment banking and use that. I agree with you, it is a very long while but banks have been known to make mistakes, perhaps this is an attempt to rectify one.

It would ring alarms bells for me. I wouldn’t use the number on the letter again. Instead find a Barclays number from their website or an email address and contact them directly to ask for an explanation.

Have you googled the phone number itself? That might give you a clue.

I’d start from the premise that it is a scam and work from there.