I'm thinking black webpages with pencil thin white fonts. You have to scroll down like 3 meters of page before you get to any content, it's just tag lines every break, staggered on either side of the page.
"After more than a century" "We revived the master" "Witness history being made at <blahhbhablh> on <date>"
Then they hold an auction, pay a descendant or two some money and book their trip to Aspen.
If you want some added legitimacy, drop a paint chip from an authentic Picasso into the mix, homeopathy style. If no one will let you do that, pay someone with some Picasso's to let you leave your paintings in the same room as them for a few weeks. Then, pay someone to write on behalf of the people who did the painting to say they "felt Pablo's spirit working through them, guiding their hand."
Get a descendant to sign off on how emotionally impactful and authentic the whole thing feels and I think you've got a high 5, low six figure painting. Do like 5 of them for your grand debut and I think we have a real RoI.
Yeah a ton of real artists will loudly decry it, articles will be written, teeth will gnash -- but I think they would sell with little to no difficulty.
For years they were ignored, but they've been growing steadily in value as they come to be seen as worthy Picasso works in their own rights.
They aren't really "new" Picassos, but they hadn't been considered as valid as they are now.