Yay!
It's possible to unpack a Sun flash archive (flar) on an Intel Box, and put Sun patches (sun4u) into it.
# flar split flarfile
# mkdir temp
# cd temp
# cpio -icudv < ../archive
# cd ..
# patchadd -R temp [patchnum]
Next stage - work out how to recombine the cpio archive and flar.
