https://ronayers.com/
Look over the parts diagrams there, get the names and part numbers. That will greatly benefit your search.
Chain guards don't typically get damaged or need replacing. If demand is a problem, you may have a problem finding one simply because nobody needs/buys them. Otherwise what you do find should be in pretty good shape.
Memory serving, I believe there is a flasher relay unit that is specifically designed to counter the hyper-flashing that is associated with the low power draw of LEDs. There will be plenty of these on Amazon. The front lights double as running lights, as well as turn signals. The rear, at least on my year/model, are only turn signal. I did purchase LED for the front, but that didn't work out because the base was too thick. Attempting to force it in only started to displace the contact in the socket; permanently damaging that socket.
The motorcycle sockets seem to have much tighter tolerances versus your average car socket; which makes sense given the shock and vibration that a motorcycle experiences. If I kept going through various manufacturers, I might've been able to find one that would fit. But I have other priorities. LEDs are also diodes. So if the polarity isn't correct or is different on the contact arrangement, either the running lights or the flashers or both won't work. There are ready-made products that replace the OEM entirely. The hangups on those are visibility and fitment. The OEM housings stick out for maximum visibility.