Everything...
A lot of this will be obvious, for example the most important things is the M42 jumpsuit, then shirt, boots, garrison cap... at that point you start to look like a trooper. After that comes the webbing and weapons. Then what?
What is most useful, what will you buy and never use and has no real practical function? Hopefully the list below will help somewhat.
The only modern item listed is a sleeping bag, as much as it seems like a good idea sleeping in wool blankets or period sleeping bags... trust me it's not worth it. You'll get no sleep and to what benefit? The public will have no idea you slept like that, you'll be cold, uncomfortable and miserable! Just hide that sleeping bag during the day. It is the only modern item that you should ever bring as part of your kit. Even things like sunglasses, ball caps, knives, lighters, pencils and pens, notebooks or writing pads, etc. should all be period or period-looking. There is no reason EVER to have modern items in your pockets or on display.
part 1... the basics
-M42 Uniform (CC2 impregnated using decking oil)
-101st patches (M42 JAcket, wool Shirt and Cap)
-wool Shirt
-jump boots (BROwn, never black!)
-trouser belt & suspenders
-garrison cap
part 2... webbing & important bits
-M1 helmet
-Helmet net (olive drab, never khaki!)
-helmet net scrim (dark colors, never light tans!)
-webbing for rifleman
>musette bag
>m1936 pistol belt
>m1936 combat suspenders
>shoulder pads
>Carlisle pouch and tin
>M1910/42 canteen cover
>canteen & cup
>rigger pouches (3-4)
>entrenching tool (t-handle or m43)
>m1 Garand bayonet
>Parachute first aid pouch (tie on)
-GP bag (specific roles only - grenadier)
-gas brassard
part 3... musette bag contents (from the original 502 document)
-1 raincoat
-1 underwear, cotton
-2 pairs socks
-2 units, heat (ask me)
-1 insect powder can
-1 halazone tablet bottle of 100 tablets
-1 toiletry set (contents unspecified)
>wash cloth
>soap dish + soap
>razor + mirror + shaving soap
>toothbrush + toothpaste (or powder)
>Tweezers + nail file
-1 huck towel
-4 handkerchiefs
-1 hawkins mine per enlisted man
-1 k ration (not the colourful morale boxes)
-1 gas detection brassard (spare)
-2 Pro Kit (VD Packets)
-1 box (3) prophylactics (condoms)
-2 British shell dressings
-m41 field jacket (optional, but it is listed!)
-1 packet of wound (sulfadiazine) tablets
-1 M1910 mess kit spoon (spoon only!)
Part 4... more interesting bits
-m1 Garand
-undershirt/vest (od or white - NO WHITE T-SHIRTS)
-wool jumper
-Zeltbahn (you didn't take a pup tent to Normandy)
part 5... trinkets & decorations​
-dogtags
-M1 Garand enbloc clips (to fill riggers)
-bandolier (full)
-scarf (woolen or cut blanket)
-m5 rubberized gas mask bag
-m7 rubberized gas mask
part 6... the list goes on and on
-1940s lighter or matches
-leather gloves (tan, not yellow)
-drop rope (I always have some for sale)
-d bars
-Compass, wrist
part 7... the list goes on and on
-Paperwork (ID Card, pay book, driving license, etc.)
-pocket litter (period-correct money, matches cigarettes, etc.)
-gas mask bag contents
>M-1 Eye shields
>Tube, anti-gas ointment
>can, anti-dimming stick, set
>can, M-1 impregnate, shoe
>Gas detection sleeve (if not in musette)
>cover, protective individual (2 max)
>Tube, eye ointment, Bal
-French language guide
-German language guide
-period watch (military or civilian)
-small sewing kit (housewife)
-pencil or period pen + writing paper + envelopes
part 8... another bit of pointless kit
-rifle cleaning kit
>oil bottle
>rifle grease pot (tiny)
>m31 brush
>pull through and brush
>rubberized cleaning kit pouch
>combination tool
>lubricating oil (can)
>bore cleaner (can)
>cleaning patches
part 9... useful items, not part of impression. But you'll want/need
-mess tin wasn't carried on person
-Knife and fork eating just with a spoon when public isn't around is just a pain
-modern 'warm' sleeping bag don't try and use an original. it'll just make you cold and grumpy; the public won't see it...
-Wool blankets really handy to have a few, after all...this is your bed!
Consumables
-hexi fuel for cooking
-matches / lighter fuel
-food / snacks
-candles
-water
