The Mach and Galil combination doesn't create static code for the Galil controller that can be downloaded to the controller and run "offline". It talks to the Galil controller constantly and streams commands to it in a very dynamic fashion. In other words, it is not a G code to Galil code converter.
I actually wrote some code to run the 1341 (VME) on an OpenBSD install on a Fanuc VME single board computer. I then wrote a TCP/IP server that mimics a Galil stand alone Ethernet controller. The problem is that you have to have a VME chassis, a Fanuc SBC, (not cheap at all) and a lot of UNIX know how. My point is that anything is possible, but it might not be worth it.
The 1040 and 1540, as Kenny said, suffer from a lack of a data record. And the 1540 also has the problem of being a serial only device. Of the two, the 1040 has possibilities but the whole plugin would have to be rewritten to even try it. The plugin is written in Visual Studio 2003 C++ (That is what you would edit the plugin code with).
Finding a newer ISA (DMC17x0), PCI (DMC18x0/2/6), or Any of the Ethernet controllers would be the quickest route to success.
Steve