Right now we have a truncated history because of some very large files in the original history:
$ git rev-list --objects --all --missing=print | git cat-file --batch-check='%(objecttype) %(objectname) %(objectsize) %(rest)' | sed -n 's/^blob //p' | sort --numeric-sort --key=2 | cut -c 1-12,41- | $(command -v gnumfmt || echo numfmt) --field=2 --to=iec-i --suffix=B --padding=7 --round=nearest | tail -n5
c82c0aee3bad 6,7MiB src/trusted/validator_ragel/gen/decoder-x86_64.c
6cac3f18ff70 7,6MiB tests/prebuilt/x64/npapi_hw.nexe
f4a2ea2025e9 7,7MiB tests/prebuilt/x64/pepper_plugin.nexe
25fd4cfb9899 80MiB src/third_party/mingw-w64/mingw-w64-src_20091116.tar.bz2
64b621604517 213MiB src/third_party/mingw-w64/mingw-w64-bin_i686-mingw_20091110.zip
But we can just delete them from the related commits, and keep the repository size low while retaining history.
If we do that we would have to rebase our existing patches, and keep the current master as old-master or something like that to keep the references alive.