Thanks, Damien, that will work for now. I did have to fix Pharo2's deprecated use of ensureDirectory in four methods first:
"Deprecation: The method AbstractFileReference>>ensureDirectory has been deprecated. Use ensureCreateDirectory".
I revised:
FileReference>>#assureExistence
 FileReference>>#createDirectory:
 FileReference>>#assureExistenceOfPath:
 and MAFileDatabase>>#uniqueLocation