New unissued/unnumbered No1 MKIII nose cap.

[browningautorifle]

Circular machine marks would indicate a lathe

I don't think they used a lathe for that...

[Brian Dick]

The nose cap pictured in post #19 doesn't look renumbered to me. It looks like the original machine marks on the bayonet boss.

[Peter Laidler]

I think so BAR but the nose cap has been mounted eccentrically. Same as the manufacture of the nose caps on Sterling SMG's was machined.

[Buster95]

Circular machine marks would indicate a lathe I would think. This is very common on rifles refurbished at Lithgow.

Look like milling (end mill) to me.