Hi Ken,
The Fletcher tone arms and reproducers were used by many off-brand manufacturers. We have seen many talking machines with these, Steinburn, Orsenigo, Burnham, and it is very similar to the McLagan reproducer with the 'hex' shape head.
FLETCHER-WICKES CO., Chicago. Established and incorporated 1918, in the State of Illinois. Officers: Elmer Fletcher, president; Roscoe L. Wickes, vice-president and treasurer; E. Norman, secretary. Manufactures "Fletcher" universal tone-ams and reproducers, "Fletcher" straight tone-arms and reproducers, Edison attachments, and Fletcher reproducers for Victor and Columbia machines.
(information copied from the Talking Machine World Trade Directory, April 1923, page 82)
Here is an advertisement showing the types of tone arms they made:
Attachment:
fletcher tonearm ad,tmw,7-23,p69.jpg [ 245.35 KiB | Viewed 275 times ]
As for the Music Master, there was the Music Master Talking Machine Co., Inc., 99 Fulton street, New York. We also have a reference to Music Master, Sturgis, Michigan with no additional information.
That auto-stop device is very interesting. Is that perhaps a Saal motor?
All the Best,