I’ve been trading emails with various people from the project after I had made my post, and helping them integrate more of Visual Studio 2003 into the project and working through a few issues to bring far better compatibility to VS 2003.
And the best part is being able to build projects in parallel!
I haven’t ordered new processors, so the 2.1Ghz parts are… lacking. However being able to use all available cores makes building DOSBox pretty fast.
Restricting the build to a single process takes 1:13 while the full parallel build on this machine takes a mere 10 seconds!
I uh, also saw this on archive.org, which may help people looking for this stuff from the future as old tools get harder and harder to find. Especially bigger editions like the Enterprise Architect version.