You need to be able to diagnose why it stopped before you'll know if you can start it again. Right now you're at 68% apparent attenuation... a touch lower than I'd want to be. If the beer is loaded with crystal malts, mashed high, ect. , it could be a matter of simply too many dextrins in the wort that aren't fermentable. If it stopped because of poor yeast health or other problem (like a dramatic change in temperature) and there are fermentable sugars left, you can probably get it started again by pitching onto a yeast cake (or massive active starter).