Buying a used car with no service history, how much of a risk is it really?

I found a car I like but the seller has no service records at all, just says it’s been “looked after” which could mean anything. My gut says walk away, but the price is good and the car itself seems in decent condition from what I can see. I’ve heard some people say service history matters less than an inspection, while others won’t touch a car without it. I saw a mention of this website as a resource for checking things, though I’m still unsure whether to bother pursuing this one. Has anyone bought a car with no history and had it turn out fine, or was it a mistake you’d never repeat? Also, if I do go ahead, what should I be checking that would normally be covered by service records? I don’t want to be naive about this but I also don’t want to pass up a good car over paperwork.