So we're collecting the existing win16 tests, updating and fixing them, and will post them to wine-patches sometime soon. At first, the test harness is going to be trivial: a top-level batch file to build all the tests with openwatcom c compiler (it's free, but not quite free enough to make it into debian), and another top-level batch file to run all the tests. (We'll also provide a batch file to install open watcom.)
Given that not many developers will bother installing openwatcom just to be able to compile the win16 tests, I suspect that might be enough of a test harness for now. Objections? - Dan