The abandoned 'Everwood' resort is actually the abandoned Aspotogan Sea Spa, intended as a luxury spa for rich Europeans. In 1994, after the exterior and roofing was finished, the German developers ran out of money. Before it was demolished in 2016 this intact and weathertight shell of a resort was popular with skateboarders.
Henry's father's medal is a close approximation of a Purple Heart, awarded for injury or death in combat. The color doesn't appear to be the purple 67115 used on the real medal. During WW2 the US had 500,000 Purple Hearts made for the expected casualties in taking Japan. They were not needed because of Japan's abrupt surrender after Hiroshima and Nagasaki. Those surplus medals are still being handed out to US soldiers wounded in action.
Audrey's London friend sent her some Vegemite and she is trying it because millions of Australians can't all be wrong. In 1902 English Marmite was developed from the yeasty waste by-products of beer brewing. Marmite quickly became an English culinary icon. In the 1910s, WW1 disrupted shipments of Marmite to Australia so the Aussies developed Vegemite from the yeasty waste by-products of beer brewing. A Londoner would likely send Marmite. Audrey's London friend is most likely Chris Brody (Jason Priestly) who told Audrey he would have been in London using his "trouble" to apply for research grants had he not decided to stay in Haven for her.