What tax on residual investment trust payment?

[Avantegarde]

Back in 2017, the Aberdeen UK Tracker investment trust closed and merged with a Backrock trust. My father, who died a short while later, had some money in the tracker trust and now, as both his inheritor and executor, I have received a cheque for £80, representing the final distribution due to him in the wash up from the trust's closure. He had chosen to have his money back rather than go into the new arrangement. So, to get to my point, should I regard this final payment as dividend income or a capital gain?