Or one of those No.8's with a guard from a No.7 grafted on to make a faux No.5 bayo?
Someone had a cottage industry making those up when No.8s and No.7s were cheap, but No.5's were in short supply.
Quite a few owners of No.5 bayos should remove their grips and take a look at how the guard is secured - unless they'd rather not know.
"There's many a slip twixt the guard and the grip! "
Got nowt Peter, or it would be in the mail to you...