The portrait is Marshall Peng Dehuai, one of the 10 marshalls of the people's republic. The reverse is a famous painting of Mao proclaiming the establishment of the people's republic on Tiananmen. Probably commemorating the 10 marshalls.
Much appreciated. In the versions of the painting I found online, one of the audience had been "purged" from the party and the painting, and was replaced with a potted chrysanthemum!