Unable to upgrade a branch

I have a branch lp:~j-corwin/openlp/pdf with format 1.6.1-rich-root
It is stacked on lp:openlp which has been upgraded to format 2a

The only copy of this pdf branch is the one on launchpad, I don't have a local copy.

If I attempt to upgrade it using https://code.launchpad.net/~j-corwin/openlp/pdf/+upgrade
Then I get an email later saying:
Launchpad encountered an error during the following operation: upgrading a branch. Not a branch: "/+branch-id/40441/".

If I attempt to do it on the command line with
 bzr upgrade --2a lp:~j-corwin/openlp/pdf

then I get

bzr: ERROR: RemoteRepository(bzr+ssh://bazaar.launchpad.net/%2Bbranch-id/40441/.
bzr/)
is not compatible with
RemoteRepository(bzr+ssh://bazaar.launchpad.net/~j-corwin/openlp/pdf/.bzr/)
different serializers

I also get the same error if I attempt to do a bzr checkout or branch.

Is there a way I can recover it, or failing all else at least get a zip/tar file of the contents since I can't even browse it online, I just get an Oops page... OOPS-306ee5e9db9983866b0bf8cf1c89e373

Thanks.