I am in a similar situate, however I am 67 and in receipt of attendance allowance which I have had for many years (bad feet). I live in Glasgow. I received a letter from the DWP alleging Benefit Fraud and inviting me to an interview! I was quite nervous about it, however I happened to speak to a friend who had used a lawyer at interview. He says that leaving it to the last minute is a bad idea. He told me that attendance allowance is a non-sanctionable benefit and this means it cannot be stopped (even if the benefits office investigation goes against me). There is also a list on the dwp website, but that is slightly different.