Tons of changes to get this closer to being buildable from this directory;
still far away, but a lot closer than it was.
diff --git a/PC/VC6/zlib.dsp b/PC/VC6/zlib.dsp
index ba0f250..42fe674 100644
--- a/PC/VC6/zlib.dsp
+++ b/PC/VC6/zlib.dsp
@@ -44,7 +44,7 @@
 # PROP Target_Dir ""

 F90=df.exe

 # ADD BASE CPP /nologo /MT /W3 /GX /O2 /D "WIN32" /D "NDEBUG" /D "_WINDOWS" /YX /FD /c

-# ADD CPP /nologo /MD /W3 /GX /Zi /O2 /I "..\Include" /I "..\PC" /I "..\..\zlib-1.1.4" /D "NDEBUG" /D "WIN32" /D "_WINDOWS" /YX /FD /c

+# ADD CPP /nologo /MD /W3 /GX /Zi /O2 /I "..\..\Include" /I ".." /I "..\..\..\zlib-1.1.4" /D "NDEBUG" /D "WIN32" /D "_WINDOWS" /YX /FD /c

 # ADD BASE MTL /nologo /D "NDEBUG" /mktyplib203 /o "NUL" /win32

 # ADD MTL /nologo /D "NDEBUG" /mktyplib203 /o "NUL" /win32

 # ADD BASE RSC /l 0x409 /d "NDEBUG"

@@ -54,12 +54,12 @@
 # ADD BSC32 /nologo

 LINK32=link.exe

 # ADD BASE LINK32 kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:windows /dll /machine:I386

-# ADD LINK32 ..\..\zlib-1.1.4\zlib.lib /nologo /base:"0x1e1B0000" /subsystem:windows /dll /debug /machine:I386 /nodefaultlib:"libc" /out:"./zlib.pyd"

+# ADD LINK32 ..\..\..\zlib-1.1.4\zlib.lib /nologo /base:"0x1e1B0000" /subsystem:windows /dll /debug /machine:I386 /nodefaultlib:"libc" /out:"./zlib.pyd"

 # SUBTRACT LINK32 /pdb:none

 # Begin Special Build Tool

 SOURCE="$(InputPath)"

 PreLink_Desc=Checking static zlib has been built

-PreLink_Cmds=cd ..\..\zlib-1.1.4	nmake -nologo -f msdos\makefile.w32 zlib.lib

+PreLink_Cmds=cd ..\..\..\zlib-1.1.4	nmake -nologo -f msdos\makefile.w32 zlib.lib

 # End Special Build Tool

 

 !ELSEIF  "$(CFG)" == "zlib - Win32 Debug"

@@ -77,7 +77,7 @@
 # PROP Target_Dir ""

 F90=df.exe

 # ADD BASE CPP /nologo /MTd /W3 /Gm /GX /Zi /Od /D "WIN32" /D "_DEBUG" /D "_WINDOWS" /YX /FD /c

-# ADD CPP /nologo /MDd /W3 /Gm /GX /Zi /Od /I "..\Include" /I "..\PC" /I "..\..\zlib-1.1.4" /D "_DEBUG" /D "WIN32" /D "_WINDOWS" /YX /FD /c

+# ADD CPP /nologo /MDd /W3 /Gm /GX /Zi /Od /I "..\..\Include" /I ".." /I "..\..\..\zlib-1.1.4" /D "_DEBUG" /D "WIN32" /D "_WINDOWS" /YX /FD /c

 # ADD BASE MTL /nologo /D "_DEBUG" /mktyplib203 /o "NUL" /win32

 # ADD MTL /nologo /D "_DEBUG" /mktyplib203 /o "NUL" /win32

 # ADD BASE RSC /l 0x409 /d "_DEBUG"

@@ -87,12 +87,12 @@
 # ADD BSC32 /nologo

 LINK32=link.exe

 # ADD BASE LINK32 kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:windows /dll /debug /machine:I386 /pdbtype:sept

-# ADD LINK32 ..\..\zlib-1.1.4\zlib.lib /nologo /base:"0x1e1B0000" /subsystem:windows /dll /debug /machine:I386 /nodefaultlib:"libc" /out:"./zlib_d.pyd" /pdbtype:sept

+# ADD LINK32 ..\..\..\zlib-1.1.4\zlib.lib /nologo /base:"0x1e1B0000" /subsystem:windows /dll /debug /machine:I386 /nodefaultlib:"libc" /out:"./zlib_d.pyd" /pdbtype:sept

 # SUBTRACT LINK32 /pdb:none

 # Begin Special Build Tool

 SOURCE="$(InputPath)"

 PreLink_Desc=Checking static zlib has been built

-PreLink_Cmds=cd ..\..\zlib-1.1.4	nmake -nologo -f msdos\makefile.w32 zlib.lib

+PreLink_Cmds=cd ..\..\..\zlib-1.1.4	nmake -nologo -f msdos\makefile.w32 zlib.lib

 # End Special Build Tool

 

 !ENDIF 

@@ -103,7 +103,7 @@
 # Name "zlib - Win32 Debug"

 # Begin Source File

 

-SOURCE=..\Modules\zlibmodule.c

+SOURCE=..\..\Modules\zlibmodule.c

 # End Source File

 # End Target

 # End Project