missing some bfk files - restore with some missing still?

i need to restore a full back up (we got hit with crypto) and its missing a bunch of the bkf files, it somehow got switched to delete after 4 weeks and my fault for not catching it. is there anyway to extract whatever bfk files i  have somehow? i know there will be lost data, but some data is better than no data. windows sbs2008  backupexec 2010 r3.4

Thanks

brian