I really like the look of the 910s and want to see if I can make them more efficient with LED.
Most of the modern LED lamps I've seen are exercises in form over function. Not that there's anything wrong with that but lamps of the 910 era did have some nice styling and a balance of form
and function are appreciated.
I've got a pair of round headlights I really like that have 55W halogen bulbs in each and those were downsized from 100W halogens. Sourcing an LED replacement for the H1 bulb hasn't been easy and is ongoing.
First finding one with the emitter placement in the same position as the H1 filament would be pure coincidence at this point. This will obviously affect the beam pattern in what I bought as off road spot lights.
In looking at the measurements (to make sure they fits behind the lenses) none of the bulbs I found show the length from the mounting flange to the tip of the bulb. I was surprised to see it in the H3 recommendation.
Another consideration is finding a bulb with low enough output to not need a heatsink or fan. There's no room in the enclosure.
I'd be willing to settle for these lights becoming conspicuity light–even preferring yellow light (not amber) instead of white. If I could find LED lookalikes that would be the better way to go but so far—nada. Style is a subjective metric.
Good luck with your search.