Hercules and Hercules unchained are being released in japan in Bluray, but i'm not sure if it will be true HD or upscaled.
https://www.amazon.co.jp/Steve-Reeves-Collection-Box-Blu-ray/dp/B07NR8BQQ2
Here's screenshots from the German DVD:
I think that DVDY (french) DVD in the DVDbeaver review looks best. More eye popping colors and better grain.
Also it seems to be longer than the German one by 7 minutes.
I'd love dozens of italian 50s-60s peplum films to be released on bluray editions a la Arrow style, but alas it seems there's no interest.
Difficult times to not be a horror fan (of course i'm saying that because every little horror b movie gets an outstanding release)