The British Museum has a number of mummies on display, so you might try
seeking their advice. You might also consider the consequence of vibration
on the mummies.

George Bailey
Objects Conservator
Australian War Memorial
Treloar Centre for Conservation
4 Callan St, Mitchell, A.C.T. 2911
Australia
Phone: +61 6 241 6122
fax:   +61 6 241 7998
email: [log in to unmask]