Remember that there are differences between the lights of the US version, and some of the other markets, where the inner lamp was the high-beam, not a fog light.
Aftermarket lights in the US should be correct, but if you source one from EU make sure it's the right one. There are lots of 7" and 5" lights around for Alfas and other Italian cars, but they don't all fit a 2lt 105. If you still have an original Carello item, check the part number so you can check if an aftermarket unit is the right match.
Start out at -
alfapartscatalog.com - go to electrical system - the drop down will take you to lighting. There you will find:
"Fog Light Amber GTV 71 - 74
Go to NAPA online.com
In the search box - key in 4412
This will take you to:
"Head Light Bulb - High Beam
The illustration will show the bulb (clear - not amber) to be 5.7 inches in diameter, with an 8-32 connection screw, and using 35 watts. Do not let the description fool you - this is not a headlamp - it is a fog lamp.
Here are a few observations about head lamps/fog lamps:
Head lamps have three 'shoulders' on the backside (rim area) that act as mounting points to fit into the head light bucket.
Fog lamps have only one 'shoulder' to fit into the fog lamp bucket.
Head lamp electrical connections are push-on.
Fog lamp connections are secured with screws.
The things you learn when you are a Bob Cozza "customer" ???