Grand rapids Cabinet Making Bedroom Set

This is a very nice Bedroom set with satin inlaid design, carved and beaded also on items. It is buried in my basement among my Mother-in - Laws other belongings since she passed away in 2001 at the age of 90. This set belonged to her parents that were married in 1898. There is a large chest of drawers, full size headboard and footboard, nightstand and ladies dressing table with drawers, mirror and stool. The stool has embroidered/needlepoint seat. The set is in excellant condition. All pieces contain the brass tag with an eagle and the imprint Grand Rapids Cabinet Making Certified with the number 9039. Also each piece is stamped with the number 424 on the wood. I am thinking of putting it in an auction, but am wondering it's real age and value. Any response would be greatly appreciated. Thanks!