Definitely the latter!.....All JM Weston shoes are huge!!!
In a dedicated loafer last (EG 65 or 100) 9 C is the ideal size for me.
My Weston "Reference" loafer is a size 8 B and even that is a smidgeon loose. (Possibly 8 A might be the better size for me.)
The length (in mm or inches) of JMW size 8 and EG size 9 is more or less identical.