> CabMAME and GroovyMAME (see my signature for links) both have the option to use > integer stretching (called "cleanstretch".
Also he could use the Windows version of SDLMAME (or compile it from MAME sourcecode if he so desired) and use "sdlmame -nounevenstretch" or whatever - if I recall correctly. No sourcecode patch needed!
That said, if someone did _just_ a patch for regular MAME to add this and submitted it, I'd campaign for it for all I'm worth.