18 Pr Mk XII shell maker BU over EA?

[Darkman]

I recently sold this Mk XII 18 Pr shell dated 7-1918 and it had a maker stamp of BU above EA.
I tend to think it’s a British shell rather than a Canadian one as it has a Lot number above the date, whereas Canadian shells usually have a 2 or 3 letter lot code below the date. But on the reverse it has a broad arrow stamp within a letter, however it’s hard to tell if it’s a C for Canada or O as a steel transfer mark. I’m 60% British 40% Canadian on this one! Would anyone know the maker please?
Thanks, Graeme

 

[Darkman]

I forgot to add this photo of the back

 

[Snufkin]

For BU/EA, the most likely firm is Charles Burrell & Sons, Thetford, Norfolk (renowned for their steam traction engines) working through the East Anglia Munitions Committee (EA).

The RS might be RSJ with J barely stamped; if that is the case then Ransomes, Sims and Jefferies, Ipswich, as the supplier of the forgings.

(Both Burrell and Ransomes, Sims and Jefferies have detailed entries in Grace's Guide.)

The attached shows RSJ 18-pr Shrapnel forging contracts for 1918.

 

[Darkman]

Thank you so much Snufkin!