Stereo experts of reddit, can you help us with our stereogram?

See photos: http://imgur.com/a/qiv7f The stereogram we have is a 1961 New Zealand built Stereophonic unit. One of the speakers has stopped working and we are wanting to replace it with a modern speaker. However the amplifier has 4 wires coming out per speaker and modern speakers require 2. Using different wire combinations we either get very quiet sound or no sound at all out of the new speaker. Is anyone familiar with this type of speaker connection? Thanks for the help!