Potential British Export Case, 75mm Mountain Gun

[Vasco Da Gama]

Pictured is a case I have had for some time, potentially a British made case for an export weapon, any thoughts would be welcome. The case is 321mm long, mouth diameter 75mm and rim diameter of 91mm. The case in question is pictured next to a British 13 Pounder Field Gun case, which is very similar. The head stamp does not follow the standard British pattern, especially the use of the Spanish word for Mountain! Could this be for export to South America?

 

[Hoeksel]

I have seen a 75x320DR90 before, could be the same case. It was marked KK 75 (meaning unknown), case made by Raufoss with a British style primer. I also suspect this to be export for a South America country.