Not the same brand, but I found a couple Miro-Flex folding relectors at a junk store, no flags tho. I refinished them & keep em in my lil car. I have another set of 3 with the lockable holder bolted to the dump box by the drivers door.

Here\'s a set from them that may be like yours on Ebay

1956 GMC 370 dump " 'Tater "
1970 VW Volksrod "the Black Bomber"
2007 Chevy Avalanche
2020 Jeep Cherokee Trailhawk,
2005 Harley Davidson FLHTCUI

I dig all cars, old and new, whether they were hammered out of American iron, German steel, or Japanese tin cans. Being unable to appreciate them all is missing out on a world of great things.
But thats just MY opinion! :P