Have an old SVN 1.1 DB corruption issue and need some help

I have inherited a REALLY old SVN server that was mismanaged for years.
They were using WebDAV successfully for so long they never noticed any
issues under the hood, but the BDB is corrupt and cannot run an svnadmin
dump on it to move it to a new server that I built that has all the latest
SVN bits.

The old system is running SVN 1.1.1 with BDB 4.2.52.

At this point after following several different pieces of guidance online
the system starts a dump, and ends up after several "Dumped revision #"
pukes out hundreds of the following lines:

svn: bdb: DB_ENV->log_flush: LSN of 56874/862249 past current end-of-log of
1/2786
svn: bdb: Database environment corrupt; the wrong log files may have been
removed or incompatible database files imported from another environment

Does anyone know where I should go from here? Does anyone know of anyone
consulting on these sort of repairs? I did a full export of the whole repro
using WebDAV before I started this, so I have HEAD, but I don't want to
lose the history if I don't have to.

-- 
Regards,
Dana