Reupholstering Arne Jacobsen Egg chairs?  

Greetings,
I have a pair of Fritz Hansen Egg chairs that have been in my family for around 50 years - a pair of early chairs. They have been reupholstered once in fabric, decades ago, and could use new upholstery. The foam beneath the fabric is brittle and "crunchy" when I squeeze it. I'd like to keep and reupholster the chairs because of the family history, even if the cost approaches that of new chairs. Does anyone have any cautions to share about undertaking the refurbishment of these chairs? Anyone know of someone who could do the work in the Chicago area?
Thanks...