More like the wooden former that the aluminum would be spun over ( on a lathe )
" When you're chewing on life's gristle, don't grumble, give a whistle "
I would tend to agree, it certainly looks like a former, i would say that the speed the prop turns would tear these glued sections apart
Yes, that is a mould for spin casting, not for operational use. that diameter is pretty narrow though for a large prop like a spitfires which is closer to 50-60 cms. It could be for a smaller two blade type set up or for a shock cone on a jet engine too.