two leather straps and a sling, origins & purposes please? 1 Canadian?

[ILH]

The last batch includes 3 unrelated items:

1)A sling, 1.5in wide, 40.5in long.
at 1st glance it looks like an early MECo example, but it is too short, doesn,t have the thick edge a Meco one would, and the clips aren't quite right......... anyone know anything about this?

2)Leather strap 1&5/8in wide by 56 in long, marked "C/I\106". it has been messed about with, rivets removed and extra holes punched. The rivet holes are 40.5in and 6.75in from the buckle end.
Is this CANADIAN, what date, and what purpose?

3) 1in wide by 69in long, marked "/I\ crown/??/?" spliced at 20-22in from buckle, holes at 3.5 to 18.5 in from tip with 1 additional hole punched at 25.75in from the tip.
I have no idea what this is from or its date although i suspect it is pretty early (1890-1945)

any ideas on these last three would be apreciated, Thanks,
Jim