as you probably know if you add /verifySafeHeaven to the url you get a pgp signed message. recently a user made a market complain accusation post claiming a dream mis-configuration and posted a link to it. I checked the signature under /verifySafeHeaven but it did not check out with the original key from here https://www.reddit.com/r/DNMSuperlist/wiki/not-listed#wiki_dream_market
now that link is listed on ddw [since they change it dynamically] yet the signature still does not check out. did anybody manage to ever verify the signed mirrors of any dream url with the linked key? maybe it is not just this url but also all others with the wrongly signed message.
In case I read your OP right, it's as simple as that: You won't be able to verify, because you are using the the wrong key. The key you linked is from support obviously, the Dream Market key is
I saved this key a while ago, u/hellfinger obviously has the same key and I was able to verify every mirror link from deepdotweb, I even succesfully ordered twice - last time from the ecleg link.
To get the dream public key: dream-mirror-link-goes-here/about -it's also described in the pgp signed verifySafeHeaven message, btw. However, this assumes, obviously. that you already have a working dream mirror you trust.