If your gona go to the extreme of carrying a spare chain shunt u carry a spare iner tube buddy!!!!!;-)
They don't exist, fact. if you found yourself in a "SURVIVAL" situation, you wouldn't have a tin off things, as if you did you would be just extreme light weight camping. it's the same with "SURVIVAL" knives, they don't exist, any knife labelled as such would be sat on the shelf as a conversation piece while you were off extreme light weight camping, Because if you had a knife with you you would no longer be in a survival situation, you would be Bushcrafting, by that I mean with a knife you can make you life very comfy indeed.
Having said that, "SURVIVAL" tins are fun to build and look at, even if it's from a "look what I can fit in this" point of view. so here's one of mine, not for a specific environment( remember you need to tailor you kit to the environment you will be in) just a box of fun.
pelicase from Ultimate "SURVIVAL" it is a kit in itself, I have added to a taken some of the bits out.
Left side: one handed blast match(sprung loaded ferro rod, designed to be still usable if one handed), very load twin tone whistle, mini kit(expanded later), Pencil, sharpening stone(very rough to quickly repair edge, can use a pebble for fine edge) heliograph(it's also a mirror for bite/parasite checking).
Right side: small stainless fine edged lock knife( easy to use and repair( though will replace with a small fixed blade when i find one that fits)), hand chain saw(cuts through 10cm hard woods in under two mins, not going to cut anything much larger than that). both sides lined with rubber non slip mat, hold the bits in place as well as catches fire from a spark and burns like inner tube.
Under the non slip rubber.
Left: 1 litre poly bag, ten puri tabs.
Right: Morse code crib sheet, international help signs, red cross help sheet, accident report form for clear casualty info recording to pass to rescue services.
Mini Kit and three snares.
Mini kit: : Four Medium stainless hooks, swivels, four shot weights, length of high pound fishing line for trace, dyneema line for main fishing line and snare trace, button compass for rough direction( not bother about exact bearings) small ferro rod, tampon for tinder, small poly bag.
All packed away, with snares held by elastic strap. whole kit weighs 500 grams.
I will ad descriptions if peeps want?
EDIT: descriptions added at 1319.