Smashing success until I actually tried to make.
1. base Squeak3.8-665
2. load VMMaker-tpr.37. save.
3. load JMMGCMonitor.4.cs. save.
4. VMM38-gc-instrument-image.1.cs. save.
5. VMM38-64bit-imageUpdates.1.cs. save.
6. open VMMaker. make all internal plugins.
   leave "64 bit VM?" unchecked!
   save vmmaker.config from VMMaker.
7. generate entire

In configuration, I noticed 2 directory related problems.  First, it
looks for src, not src32, probably because svn 1100 predates that.  I
used the config arguments to straighten it out.

Second, my "top" directory is not called platforms.  In a couple of
instances, the config script generated messages indicating it was
still looking there:
checking whether doubles are stored in Squeak order... no
../official/unix/config/configure: line 21858: cd: /usr/local/src/squeak/platforms/unix: No such file or directory

checking for FFI support... ../official/unix/config/configure: line 24996: /usr/local/src/squeak/platforms/unix/plugins/SqueakFFIPrims/ffi-config: No such file or directory

The make proper was awash in errors.  I don't know if it's the
directory problems or a versioning issues:
gcc -g -O2 -fomit-frame-pointer -DLSB_FIRST=1  -DHAVE_CONFIG_H  -DSQUEAK_BUILTIN_PLUGIN -I/usr/local/src/squeak/bld -I/usr/local/src/squeak/platforms/unix/vm -I/usr/local/src/squeak/platforms/Cross/vm -I/usr/local/src/squeak/src32/vm    -c -o interp.o /usr/local/src/squeak/src32/vm/interp.c
/usr/local/src/squeak/src32/vm/interp.c:5:16: sq.h: No such file or directory
/usr/local/src/squeak/src32/vm/interp.c:7:28: sqMemoryAccess.h: No such file or directory
/usr/local/src/squeak/src32/vm/interp.c:9: error: syntax error before "printCallStack"
/usr/local/src/squeak/src32/vm/interp.c:9: warning: data definition has no type or storage class
/usr/local/src/squeak/src32/vm/interp.c: In function `error':
/usr/local/src/squeak/src32/vm/interp.c:13: error: syntax error before "printingStack"
[etc]


I was using the remote build style so I had
src32/
official/  # usually known as "platforms"
bld

So my configure was
/usr/local/src/squeak/bld$ time ../official/unix/config/configure --with-src=src32