Should be able to claim pension credit, which tops up weekly income to a minimum of £227.10 for single person. However, more importantly it acts as a gateway to other benifits, such as council tax relief free eye tests & glass and free dentist etc. Pension credit tops up weekly income to a minimum of £227.10 for single person
If he has £10,000 or less in savings, it will be disregarded, every £500 you have in savings over £10,000 is counted as £1 in income a week when your pension credit is calculated.
As @Joss says phone age concern and I’d advice they or welfare rights, citizens advice help him claim whatever.