I have (4) unopened tapes and a few
"beaters" that seem to still work
 so this may be all I can work with going forward--  unless a replacement
 belt scheme pans out. 
    Chris, what is the problem with recovering a DC100A for service? If I'm
not mistaken I have some tens of these tapes stored...Is it expensive where
you live? Shipping from Brazil would be expensive for a free pack of 10 or
20 tapes?