Im not sure they are the same, but on my UA and a friends Horizon, the fixtures are sold at walmart for about $20.00 for the pair.
I also found the bulbs at most auto parts stores. In my case, my fixtures were almost impossible to get apart due to the corrosion. Before I found the fixtures at Walmart, I had already purchaced and modified to fit some other driving lights. They work... But I would have rather had the originals.
To remove, again on my unit, it was pretty easy, just remove the bolts around the fender skirts, lift up (hinged), and remove the backing shield. The fixture unbolts from its mounting place.
"It's always wrong, everywhere, for anyone, to believe anything beyond insufficient evidence" -- William Kingdon Clifford
John (N9MXX) & Derek (KC9KEM)