I got the following from a UK person (not sure which country or if it is correct, but I sure do not know). I collect USMC but buy any Militaria item I think I can sell or trade, been doing it since 1960.
(Quote): Hi- what you have here is a WW2 Canadian Bren Gun Spare Barrel bag, used for carrying a spare barrel for the Bren gun along with cleaning rod, spare parts and various tools. The makers mark is Z.L & T. Ltd which stands for Zephyr Loom & Textiles Ltd, a well known CDN maker of webbing. This was carried by the number 2 in each infantry Bren machine gun crew. Cheers,
The next info is off the web and about this manufacture:
Here is some info on the Canadian maker.
Whilst there is solid evidence documenting limited Canadian production as early as 1924, two Canadian firms began producing web equipment in earnest in 1940 (pre-production pieces have been noted with 1939 dates). These were Zephyr Loom & Textile (ZL&T) and the splendidly named Montreal Suspender and Umbrella, Ltd. (MS&U). Neither firm had the special looms needed to duplicate M.E. Co. and M.W.& S. products. Without these looms, Cartridge Carriers, Braces, Pistol Magazine Carriers, Pistol Ammunition Pouches and Holsters, all of which entailed either integral, or reduction weaving, had to be constructed differently. Thus Patt. '25 Cartridge carriers made in Canada can be readily distinguished by their folded and sewn pockets.
Richard PS: sorry photo did not download