After some helpful pointers in email, I've gotten MOST of a 
new system built.

However after:
Downloading a new gnu.tar.gz source set
Downloading the entire gcc sub-structure from ftp.netbsd.org

I still see this after a make depend then a make after
cd'ing to src/gnu

===> usr.bin/gcc/g++
===> usr.bin/gcc/libgcc
cc -O -I/usr/src/gnu/usr.bin/gcc/libgcc/../common -I/usr/src/gnu/usr.bin/gcc/lib
gcc/../arch  -I/usr/src/gnu/usr.bin/gcc/libgcc/../arch/i386 -nostdinc -idirafter
 /usr/netbsd/usr/include -c -DL__gcc_bcmp -o __gcc_bcmp.o /usr/src/gnu/usr.bin/g
cc/libgcc/libgcc2.c
/usr/src/gnu/usr.bin/gcc/libgcc/libgcc2.c:76: no data type for mode `XF'
/usr/src/gnu/usr.bin/gcc/libgcc/libgcc2.c:82: unknown machine mode `__word__'
*** Error code 1
                           
Is this an error, or my lack of understanding?