Who stole it and where is the Quidditch World Cup trophy?

The carved boar's head among the belongings of the thief vanquished by Winifred Wartbobble is a piece of  artwork from the Black Forest of Germany. I think this is the biggest (and as far as I can tell the only clue) to the location of the hidden trophy. The peruvian darkness powder and hand of glory were clearly used to hide the trophy. This location fits the hints some of the quidditch captains have provided, describing the location of the trophy as 'more specific than a country, less specific than a city'.

I believe the thief himself was a vampire! Winnie's missives have contained several veiled references to vampires. Among the thief's possessions are some bloodpops - confectionary of vampires. Also at one point she went to visit Horace Slughorn to get information from him. He was very good friends with Eldred Worple, befriender of vampires, and author of  'Blood Brothers: My life Amongst the Vampires'. In fact I think it is possible that the thief may even be the vampire Sanguini who was in company with Mr. Worple at Slughorn's Christmas party during Harry's 6th year at Hogwarts. We know that vampires are associated with the Black Forest because Quirrell claimed to have encountered one in his travels there. A possible further association of the clues with vampires is the fact that Whitby museum is one of only two locations in the muggle world to possess a true hand of glory, and Whitby is where Bram Stoker stayed whilst he chronicled the story of Count Dracula, the most famous vampire of them all in muggle lore.

However, I really fail to understand the significance of the Swiftstick broom, the snitch and the broken wand, beyond the obvious association of the broom and snitch with quidditch, and the possibility that the wand was broken during the vampire's fatal duel with Winnie.

And that's my final say on the matter (I think!)

(Incidentally, the Black Forest was the location of mine and Mr. Wigworthy's honeymoon!)