Pete-Below is an image of an Alternator kit that I had assembled for my 100-6. The overall assembly fits in place of the Generator using existing mounting points on the engine Side Plate backet and allows for the coil to mount onto of the Nippon Denso Alternator. The mounting brackets are available from Moss and are Triumph mounts. I used threaded rod with a tube sleeve between the mounting lobes on the side cover plate.
The bracket to mount the coil was shaped at home using a vice with multiple bends. A little trial and error to get the bends and file out cuts for clearance.
When assembled the entire kit looks good, has clearance and you can mount the coil and its mount on top of the alternator. You will need a dummy regulator from Moss to complete the changeover as the Nippon Denso alternator has an internal regulator.
Notes-
I used a "one wire alternator" and added a voltmeter to confirm charging. 12.4 vdc with engine on but not started, 13.5 with engine started.
Triumph Brackets will need to be drilled out for existing mounting hardware.
Brackets-Moss $18
Alternator One Wire-DB Electric or Amazon $100
Metal Flat Bar, all thread, hardware, tube sleeve-Hardware Store $25
Dummy Regulator-Moss $70
Voltmeter-Amazon
Engine Paint-Moss $30 Note plug holes in Nippon Denso Alternator if painted that way paint does not get onto the windings.
Tools-Drill and bits, vice, hacksaw to cut all tread, metal file.
Thanks to Steve Gerow for alternator selection and source for the brackets.
Feel free to reach out to me if this is of interest or should you have any questions.
Peter.