Offhand I do not know but doing a quick search turns up a couple of possibilities.
I cannot see much detail in the Packards front on view to tell what kind of pattern might be in the lens but there is a place that sells what they call a cats eye fog light lens in 5".
http://www.2040-parts.com/vintage-cats-eye-fog-light-lens-5238-5-inch-i1413406/ While it says USA it looks like there is a foreign language map on the page so no idea what that is about. Not sure I would fully trust that sight but maybe worth getting info.
Possibly some of the inexpensive aftermarket fog light kits have a separate lens and a pair of those was bought and disassembled for the lenses. Summit has some that says clear bulb, amber lens but from the photo you cannot tell if the lens is actually a separate item that is a full 5" or is bonded to the bulbs like some of the 6 or 12v replacement bulbs only that are available on ebay .
https://www.summitracing.com/parts/upd-c364007/recommendedparts It could be the overall light housing is 5" but lens is less as I see a few lenses on ebay at 4 and something inches.
With either of those options there would be the question of how to mount the lens as there are no screw holes.
There is also a possibility that someone has used a transparent glass stain on a pair of existing Packard clear lenses for the amber effect. Have also seen lots of cars running around with amber bulbs behind the stock lens.
This Post was from: https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?post_id=225703