Just to provide an update from the UK side of the pond. UK airports now permit a bladed item with up to a 60mm cutting edge. I inadvertently turned up at the security check with a pen knife in my pocket. It was checked by the security agents and handed back to me to take on the plane.

I think a straight razor is going to be too long but a DE should be fine flying out of the UK now. It might still be a little hit and miss depending on the agent so don't try it with anything you can't afford to lose.