Is Dirac's algebra Dirac's algebra?

Paul Dirac had definitely contemplated quantum operators at unequal times prior to his 1948 paper on the quantum theory of localizable systems. And although he did at times cite related work of others, he seldom referred to inspirational conversations. There does exist evidence, discovered by Yin Xiaodong, that he had had significant interchanges with T S Chang at the Institute for Advanced Study in Princeton over a six month period beginning in the Fall of 1947, and this was concerned with the quantum algebra that arose when altering an arbitrary spacelike surface in Minkowski space. In the context of general relativity this metric-dependent algebra will have a profound impact on an eventual quantum gravitational theory. I will sketch its development, beginning with the work of Paul Weiss and focusing in particular on an interpretation forwarded by Peter Bergmann in 1962.