Buy new if you can. You have no idea where that mil-surp medical is coming from and I wouldn't trust a TCN's life on it. Northern Rescue runs sales pretty often that will give you a decent medical kit eventually.
Don't worry about TC3 - treat at the level you are trained to. You can carry LR, Hextend, NCD, and a crich kit... but, its worthless if you are going to do more damage applying it or not knowing contraindications.
Identify what things you could encounter on your mission. Going to Disney World; Light on trauma and heavy on sick-call. Visiting Gaza; heavy on trauma and light sick-call.
Nice, minimal GP trauma bag:
- 2 Israeli
- 2 abdominal
- 1 SAM splint
- 4 sling and swathe
- 2 CAT
- surgical tape, sharpie, shears & blue chem-lite
- 50 brick of 4x4
- 1 combat gauze (NO granulated)
- 2 nose trumpets; 30 & 34
- 4ea ketchup packets of lube and burn gel
- travel bottle of 500mg Ibuprofen and 250mg Naproxen (Know the contraindications)
- Maaaaybe an Asherman$$$ if you want but... you can handle the same task with cigarette cellophane and tape if you have to
Editing to add-
Hell... yeah, can't believe I left out what 1bama said above me. Kerlix and Coban were my staples. Good call sir!
Second edit: I guess I got carried away and got lost without answering your question :)
Buy new supplies. We audited supply every 3 months and *anything* out of date went straight to the dumpster. If find medical at a surplus store, I would wonder how it got there.
Don't get hung-up on 'civ -vs- mil' supplies. They all do the same thing when applied properly.