I just discovered that there's an old package already called mscompress which contains an msexpand binary. This binary seems to support fewer formats than the one from libmspack though.
Notably MS-DOS 6.22 files cannot be extracted by the binary from the mscompress package. Fedora also uses expand from libmspack to provide the msexpand binary instead of mscompress. My suggestion would be to remove the mscompress package and replace it with the binaries from libmspack.
