Pocket Flask - Glass, Leather, Metal

I was looking for some English Hallmarked Sterling flasks and came across this interesting bottle. I can't date it (any suggestions?), but it's in good condition. The metal cover screws on and seals tight. The leather may be be faux snakeskin and is in very good condition. The metal cup may be tin or plated brass - no rust. I may trade up in the future for nice sterling, but for now this a keeper.