Kevin McElhone of the MBSGB published a catalogue of Gem roller cobs
about two years ago; both 20- and 32-note types are included.  Regarding
the MBSI list Angelo Rulli described, I'll leave it up to the authors to
decide who was first!

Copies of Kevin's catalogue are available from MBSGB, 47 St. Johns Road,
Kettering, Northants NN15 5AY, UK.  The cost is US$17 including postage
to the USA.  Cash requested if not paying in Sterling, because of
punitive bank charges.

Kevin is an indefatigable collator of lists, and his Cob list is just 
one of many.  I'll get a complete list from him and post it, as it may 
be interesting to others to know what's already been done to avoid
duplication of effort -- as the recent MBSI article suggests may have
happened in this case.

Julian Dyer