Archibald Currie and Co.Flag

I am trying to identify a shipping company from it's house flag. The flag is white having a red cross in saltire with a solid diagonal blue square superimposed upon it. The illustration I have I estimate as being mid 19th century.

I have found this Australian Company: Archo. Currie & Co of Melbourne.

The eleventh company on the BIShip page about companies affiliated with the British India Steam Navigation Co. is Archibald Currie & Co. (purchased 1913). (I think “Archo.” above is a typo for “Archd.”).

White flag with red saltire, a blue lozenge placed over it in the centre. Jorge’s version has the lozenge large, the BI site small. Lloyd's Flags and Funnels [ll012] shows it large again, bolstering up Jorge’s version.

The founder’s biography at the Australian Dictionary of Biography describes the company as having a small but excellent fleet and famous for transportation of horses.