Removing adhesive from aluminum

We have a small collection of aluminum store tokens which were glued
to burlap using rubber cement about twelve years ago.  The tokens
were removed from the burlap several years ago and gently cleaned
(Orvus WA), but a hard yellow-brown crust of residue remains.  Our
resources are very limited--can the residue be safely removed
in-house?

Larry Hutchings
Stevens County History Museum
116 W 6th St
Morris, MN 56267
320-589-1719

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                  Conservation DistList Instance 9:78
                   Distributed: Friday, May 24, 1996
                        Message Id: cdl-9-78-014
                                  ***