Now English Buildings has suggested a fourth site for his burial. Writing of St Wystan's church at Repton in Derbyshire, the blog says:
It’s quite unusual for a parish church to have a crypt. You usually find these underground spaces beneath large cathedrals, where they housed sacred items such as the remains of saints. Parish churches didn’t often run to such precious relics, but monasteries sometimes did, and the church at Repton began as a monastic church, and an important one, that became the burial place of the kings of the Saxon Midland kingdom of Mercia. King Ethelbald of Mercia, who died in 757, was buried here; so was King Wiglaf (died 840). When Wiglaf’s grandson Wystan was murdered, he was laid to rest here too. When Wystan was canonized, Repton became a place of pilgrimage.