Turns out it isn't a laptop. Now bare with me, the way he explained it, it's a computerised, high frequency thingamadoo that bombards your body with vibrations which kill 60% of naughty we gremlins in your blood/body. Apparently, different body bugs die at different wavelengths, so the on board computer scans your body and then zaps them - wave at a time. I asked if it also made a cuppa - he seemed not to recognise the words. It comes with its own adaptor/transformer with American pins. Input 120v ac 12W. Output 9v dc, 500mA.
The numbers probably work, and he's been using it on the bathroom shaver he already has installed for a number of months. But I'm not really happy about installing what is, despite the label, an american style socket in his sitting room. Besides, if he can purchase an HF Thingymadoo, then who knows what else he can plug in later.
So, I have to get the transformer for him. But, on the good side, we got on well, and he's considering building an outhouse in his garden which he'd like me to price for a supply and fitting out. Bad side, the FB is an old insulated Wylex with rewirable fuses :-(