Welcome to SRP, thats a fantastic looking razor you found there, and a family heirloom. The horn scales and mother of pearl insert looks to be in very good condition.
WM Gilchrist was an importer of cutlery, so he didnt sell the right to Wade and Butcher, manufacturers produce cutlery and razors for his company. Im sure you are aware that a Gilchrist pocket knife was found on Abraham Lincoln when he past away.
An interesting newspaper clipping from 1861.
Attachment 141034
Attachment 141035
Attachment 141036
Lastly, being a family heirloom and all you should really consider sending this razor out for restoration and honing, and then use it!