I took a quick tour through my 3 References (Windsock Data Files #4, #115, and their Special on the Bristol Fighter) and from the photographs that showed a pretty good view of the prop I'd have to say metal edges were not nearly as common as those without. Most common was the painting of the blades to varying lengths with a grey paint, whether this was for protection of the prop from chipping etc. or possibly an anti-glare measure I don't know.
Hope this helps answer your question.
Cheers,
Lance