I have to say, the word "Lightolier" seems to open doors in searches, compared to "L".
I ordered these at Wayfair:
https://www.wayfair.com/lighting/pdp/wac-limited-charge-led-line-voltage-track-head-wacl1200.html?piid=38257295%2C38257297
I'll keep you posted. That's a lot of money just for lights ... but the hallway is pretty narrow and dark (remember, 70s ranch), so it will be a nice upgrade.
G