That is a lovely old girl.
Either the rifle was issued and brought back in for repair, where it lost the original scope, or it never had a scope mounted on it.
There is no serial number on the top of the butt wrist, so I suspect it was never issued.
The scope and bracket on the other hand may be marked to each other. Can't tell from the pics.
The bayonet of course wouldn't have been issued with the rifle. Especially with the parade nickel plate on the scabbard.
To my knowledge, No4 MkI T rifles weren't issued with bayonets nor intended for use with them.
Attaching a bayonet will change the point of impact when shooting it.