Seems like there are a lot of places selling those German Army coats.
I just got the Blu-Ray of The World's End yesterday. Spotted the hospital bracelet, but I haven't got a screen capture yet.
One thing I did notice is that older Gary is definitely wearing Levis - you can see the red Levi's logo and a standard brown size patch pretty clearly in the special features documentary, when at one point there's a rear view of Simon Pegg as he flips up his coat. Now here's an interesting thing - there are only three styles of Levis selling at Levi's UK that are black with a brown size patch: One is Levi's 501s, but at 17" the leg opening is definitely too wide. another is Levi's 506s in the color 'Moonshine'. However, 506s have a 17.5" opening, which also seems too wide to me. The other is Levi's 504 in the color 'Pistola' - these have a 15.75 leg opening, which seems about right.
Also, as an interesting little tidbit, the makers of the Blu-Ray mention the fact that all of the band names that the characters make up as a running joke have been made into T-shirts by fans. Kind of a shout-out to those of us who are World's End geeks.