Antique (3) Steel Tuning Forks circa 1920's Philharmonic, C D E F Adjustable

Description

Interesting group of tuning forks found in an old music repairman tool box owned by Raymond Miley Uhlig  who worked for John H. Troup Music House in Lancaster, PA in the late 1940's. (Have some pay receipts from 1946-1948)
The adjustable fork has sliding blocks that line up with scales on the sides. No name, but does have 2 sheild marks on the blocks and the base of the tool.
One tuning fork is marked "C" and has the number "C522" stamped on one fork blade. Has a brass ball welded to the handle at the base.
The last is well marked "Philharmonic C" on one side and "Valantine & Carr Sheffield, England" on the other.
All are in very good condition. I am not a musician, so I cannot vouch for their accuracy at producing the correct tone.
Will ship in padded envelop Priority Mail.