Greetings,
I've published the current version of the script used to maintain the Linux Linaro kernel trees. It is still at early stages of the development, and has a big room for enhancements and improvements. Nevertheless, it can recreate the earlier trees from the pinned manifests (and do some other stuff). For some more details see
https://wiki.linaro.org/Platform/DevPlatform/LinuxLinaroKernelTreeProcess#Li...
If interested, you can use ll-fold.sh in the way described at the wiki page above at your own risk :)
Thanks, Andrey