It is certainly part of a Rotol propeller. Rotation is RH, which precludes later (Griffon) Spitfires and the big radials which went in the Wellington, Lanc, Halli and post war stuff.

It looks rather like a Mk.9 (Merlin) Spitfire blade to me.

The “welding” (actually soldering) was quite normal on the brass anti-erosion strip. It made negligible difference to the operation or efficiency of the blade.

Anon.