Hi all, I have not posted for quite awhile.
Presently I am working on an HT1 for a friend. My friend did a great job of restoring the bike but he brought it to me to sort out some electrical issues. The last issue is that on the headlight both filaments are blown out . I checked on ebay and HT1 headlights are VERY pricey, approx. $200 . I was hoping to find a 5 inch headlight with an H4 bulb that I could fit into the headlight bucket, but no luck yet. Any members out there know where I might obtain a good HT1 headlight?
In previous years I obtained 5 3/4 inch headlights with H4 bulbs for my CT3 and RT2 from Octain Lighting but I went online and they do not list a 5 inch headlight with H4 bulbs, so no luck there. Any help would be appreciated.

You can use the AT1 headlight with replaceable bulb, correct wattage 6v bulb is like $2 on Amazon.  I sold the two I had.  (I sold mine way too cheap!)

Here's one but you'd need the pigtail/bulb retainer (which can also be found, even aftermarket I think). 

ebay headlight

Thank you very much Mark. As I really have not worked on the AT1 models so I was not aware that the AT1 headlight is also 5 inches.
Don

I'm not sure on headlight sizes but i possibly incorrectly thought HT1 up to RT3 were the same size but i'm happy to learn.
But what i was gonna say is fit an AC 6 volt single wire bulb saving regulator.
They should've had those from the get go.
But don't think they'd been invented then in 1970. Saves the day--& your pocket-- in the event of the battery running dry or not fitted at all.
Here's mine as found, the day it arrived home  lol.
Didn't look much better when i sold it but it sure performed well.
photos.app.goo.gl/gidrkb9wadBSYRGf9

I’ll look this weekend to see if I have one