Old uncashed cheque from Solicitor - England.

Can we claim a solicitor’s cheque from 2013?
My wife re-mortgaged back in 2013 and some part of the process involved the solicitor sending her a cheque for £1000, which she didn’t cash at the time unfortunately. We were selling the house recently and I came across this cheque, we contacted the solicitors who are still active (but not accepting new clients) but didn’t get anywhere despite a few phone calls. We have the letters and the original uncashed cheque.
I have read about residual client balances and a few other pages, but I don’t know if some kind of time limit has been reached for the chair to be reissued, far from an expert in this area. Could anyone give any advice on how successful we could/might not be with this please?
House is in England, we were in England at the time and still are, as is the Solicitor.
Thanks to all in advance for any advice.