False widow?

[bernhund]

Opened the lid of the mains stop cock out in the street at my mum's house this week and spotted a spider with a couple of smaller ones. Not one I'd seen before and I now wish I'd taken a photo. It was about 2cm with very black high gloss legs (not hairy!) and a round pale brown abdomen with a couple of spots on it.
I've Googled False Widows and seen quite a variation in them, but didn't see any quite the same as this. What do you think?