They are from a '68/'69 Datsun 510, might have gone up into the early '70s. There are easily available reproductions, but the repros have two small screws that hold the lenses on, unlike the originals. For the repros, do a Google search on "1968 Datsun 510 side marker lights". Here are a pair of the repros for $25: https://zcardepot.com/collections/lights/products/side-marker-light-frotn-fender-510-1968-70 The vendor says they are slightly longer than the USA version. They also look slightly different in shape than the originals, at least to me.
NOS is available from some of the Datsun parts vendors, but are somewhat pricey. Here are some on eBay, but you could also search the various Datsun 510 parts suppliers. A little more pricey than the repros: https://www.ebay.com/itm/112889815433?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&mkscid=101&itemid=112889815433&targetid=1645685073288&device=c&mktype=pla&googleloc=9009606&poi=&campaignid=20133407470&mkgroupid=147476396765&rlsatarget=pla-1645685073288&abcId=9312979&merchantid=113531919&gclid=CjwKCAiA9ourBhAVEiwA3L5RFr0EzSFQYq2YQfhxJM3NkHdt4FOvb0YuqaQVXpk-QF9wf3tCRB_cOBoCpdEQAvD_BwE
Even though I had several modified/hot rodded '68/'69 510s in high school (early 1970's), I can't remember for sure if the orginal marker lights were a different part number for left and for right. I no longer have my 510 parts catalogs to check on that.