Jeff: my ‘41 has been converted to double contact 6 volt 1154 bulbs so my parking lamps also work as turn signals. I thought I had a single contact lamp in my stash but I couldn’t find it.
Jeff,on my '37 i have some new led parking bulbs that i got on amazon are #55 trade number equivalent. they work well and are whiter brighter than the incandecant oe. Tom.