large slot drill sidelock chuck for lathe

[Toolmaker51]

Hi Toolmaker51

Here is the photo of milling cutters and identification

The left in the UK is an End Mill and the Left a Slot Drill
Yes, partially. In US both are endmills, capabilities ID'ed by number of flutes.

A shell mill is like an End Mill but is bolted to an arbour
Yes, exactly.

Side and face and slitting saws fit to a Stub Arbour.
Yes, exactly, or that of a horizontal mill. Full length arbors aren't named that I know of, stub is self-explanatory.

Deadlock cutter is screwed to an arbour with a realise mechanism built in the arbour via to dog grub screws one tightening the cutter and the other to release
New to me, 100%

Are the names for these items the same in the US? Yes.

The Home Engineer

Unsure [spelled no clue] on Deadlock, so googled it. LOL, got identical ebay page, at 93 something Euro's as your pic but no description or amplification otherwise. No recollection of screw-on cutters beyond countersinks; I guess a right hand cutter uses left-hand threads, retained by grubs?
Other deadlocks were door hardware. Those I recognize easily, house full of them, circa 1902.