Hi Shaun,
Great looking carrier you've got and also to uncover most of the original marking's

Unsure if you know about this web site but have a look at it! it may help you! special with the yellow circle on the front gaurd.
www.axholmesigns.co.uk
I found it when I was looking for British marking's that are on my Fordson WOT2-H, as you can see via the photo on the passenger door and the Driver's side front gaurd it has the yellow square with the number 14 marked inside it.
The web site state it represrents "B" Squadron unsure what that means maybe you shed some light on it for me Shaun.
Kind regards
Ian