Jardine seemed to be leaders in the field of countershaft boxes, and then to fade from the market.
Too expensive? Too complex?
Lots of folks used a 'starter' involving a short run of chain - but as with just about anything at the time which was a 'fad', there's a myriad of different ways of doing it - lugs under the chainstay, lugs above the chainstay, a few with the starter on the saddle stay, bolt-on apparatus rather than braze-on lugs (presumably to 'update' an existing design with the minimum of effort).
There was even an article in the Blue 'Un about them, with the usual line drawings - it seemed to be the next step on from the conventional bottom-bracket pedals, and another step away from the cycle heritage. By 1915, stuff without a proper gearbox was starting to look a bit 'old hat' though.
The only machines I've seen the 'eye' casting on are a very nice 1914 Precision v-twin, and a Sun-Precision, which places it forward of the brake lug, for a longer chain run. edit: and the Regal ladies model outfit for 1914...