If you own a modern Triumph twin you have to like the sparse clean stylish look of the 60s. Unfortunately the bubble tail lamp does not fit the part.
  Lucas tail light adapter / turn signal kit. Lamp housing incorporates signals.
Easy bolt on adapter plate makes seamless fit on fender as if it were factory designed. Bolt on and go.
Perfect fit on Bonneville, Thruxton and Scrambler fenders.
Mounts in a high visible position and importantly, sits at the correct angle on fender.
 Kit uses existing fender bolt holes that adapter plate mounts to retaining the anti vibration rubber mounts as on stock lamp, giving traditional style and modern reliability.
Stock harness is utilized and crimp on, silicon sheathed tin plated Honda connectors supplied. No splicing required just an exchange to smaller connectors.
 If using this kit on Bonneville models with headlamp ears, turn signal blanks and spacers are rcommended.
https://www.maundspeed.com/product-page/turn-signal-blanking-biscuits