Deagan 1920 Dinner wall chime military bell xylophone antique vintage A440 A=440

Description

Deagan A 440 single chime. Date unknown, closely resembles other multi bar dinner chimes from the 20's.
Top of chime says JC Deagan Inc., Chicago, Made in USA.
Below the first screw shows A=440 followed by (I think) the words Vibrations Guaranteed.
Below that engraved sideways
Official Pitch A.F. of X 1917
Adapted by US Gov't 1920
Based on the second set of inscriptions this may be a military dinner bell, but uncertain.
See photos for condition. Kept indoors but not temp controlled.