This build number is in file "OLECLI.DLL" from Windows for Workgroups 3.11 build 411. The file version table states that the Product version is 3.10.0.101 (RC1).
It is also mentioned in Microsoft antitrust document PX01251 from February 1992, alongside builds 71, RC1, RC2 and all compiles of RC3 (a-g). The document lists several app issues with this build.
