Very nice set, but not 1915.
The 1915-17 have the focus screw at 12 o'clock (above the socket) while the later ones have it a 9 o'clock relative to the socket.
Note too that the sockets were different as well. The later bases are tapered and fit different fender trons
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From the Forum Encyclopedia
1915 HEADLAMPS
(All lamps appeared alike, regardless of make. Early production 1915 lamps varied; made by E & J, they had larger brass rims and lenses (8-5/8 vs 8-1/8”) than later standard style lamps. Lamps were supplied by E & J, Brown, Victor and, perhaps others.
Headlamp lenses were clear glass until 1921.) Steel headlight rims specified in a letter dated June 19, 1915.
6511X with large lens rim. (E & J 456)
6511X with brass lens rim. (standard)
During the latter part of 1914 and perhaps early 1915, headlamps were fork-mounted, on the same forks as used by the carbide lamps. Early in 1915 the lamp with the riveted-in-place post became the standard. All were electric, powered by the magneto with the bulbs wired in series. Brass rims discontinued about June 1915.
1916-1917
Head, Side, and Tail lights were now all painted black but continued the style of 1 915.
Identical to the later 1915 lamps except for the elimination of the brass trimming. Painted all black.
1917-1919
HEADLAMPS 6511BX
In late 1917 a dimmer was added to the light switch on the magneto-powered lamps. The lamps appeared the same as the 1916 style except for the use of bulbs with two contacts (6-8 volt, 16 C.P.) instead of the older single contact type (8-9 volts, 18 C.P.).
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Rims for round glass had small claw like tab while H glass has a straight bar.
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