There are 4 SE23 addresses on that list.
But before anyone starts a which hunt,

1. the compilers of this list (BNP) are hardly trustworthy in the first place,
2. this is raw unmaintained data without any mechanism to correct mistakes now it has been leaked,
3. It is not clear if these are members, people who have asked for material for research, potential recruits from other data sources, or ironically perhaps people who have requested BNP's offensive literature is not delivered to their address.

So it would be wrong to draw concrete conclusions about any individuals listed, some who will never had any contact with this organisation, let alone be fully paid up members.

But putting that to one side, publishing their political views is a gross breach of their rights, and while they might not have any concerns if the (jack) boot were on the other foot, that does not make it right.