Get Sandra Romain, Tiffany Mynx, Gianna Michaels and Belladonna to come out of retirement just for one day in a massive no hold's gangbang orgy.
Even with piracy, I have no doubt each dame would make a million $ at the very least. And even if my cast list would not rake in the $ I purport, I am sure others can put forth a list that might.
Porn is getting kinda boring.
Think MMA type promotion versus boxing which hits only one true pay day every 5 years.

Seek out porn stars we all thought we'd never see again.
Make them an offer they can't refuse. Focus on vintage "where are they now" type models. And even recent "never thought I'd see you again" types.
Who cares what Bambi from Debbie Does Dallas looks like now? Put her in a movie & she's a millionaire off the get go. And so would others I can't even begin to fathom. So, porn makers, what say you?
Start a series based on this concept. The longer in between probably the better as I am sure it would take time to conjure up a cast.
Loni Sanders, Lisa De Leeuw, (back from the dead) fucking Shane from the Seymore era while Bobbi Starr, Sasha Grey, Gauge & (input your fantasy actress) fluff in the background in anticipation of the next series with some not going all the way. "Will they or won't they" type scenario.
Yeah, I might smoke a bit of green but all things being equal, if this could happen, how does everyone not win?
And yes, many might turn down the opportunity even if offered a ton of $ but some would probably make a brief comeback. Of this I am certain.😎