Hello andi9876,
I found several signs with the name "National Road No. 6A" at least extending north to the intersection at [node](https://www.openstreetmap.org/node/441032355). If you believe that they are old signs then I agree with you changing it to the old name. Do you have an updated source showing that the name has been changed? Here are some of the signs that I found: https://www.mapillary.com/app/?pKey=141815801824557
https://www.mapillary.com/app/?pKey=1358871771603050
https://www.mapillary.com/app/?pKey=529453379082485

Please let me know if you have any questions.
Thanks,
GbabethemapGod