The problem here is that modified Hellcats/Redeyes are worth less than stock ones. There's a sucker born every minute, and maybe people can try and flip a modded car. However, the same can also be said about trying to flip a car with a salvage title. It might look and drive perfect, but a salvage titled car is going to be worth 30-40% less than one with a clean title. A modified Hellcat comes with a litany of issues. Who did the work? What's the quality like? What parts were used? Then you have issues with the tune and depending on the state it gets titled in, it could have emissions problems. And so on.
Thus, as a broker, my radar goes up when I see both a modified HC for sale, and for what really and truly looks like an exorbitant price. A P1400 code HC has no manufacturer warranty, it is exempt from any extended warranty, and it offers little to no peace of mind for the buyer. There is just no benefit to trading/dealing with a modified HC. Sure, people mod and drive them... but each and every one of those builds is a unique build. Just because one works fine doesn't mean the other one won't spit out a halfshaft or the blower tomorrow. To add insult to injury, according to the OP, the car was modified and driven only 1,000mi... meaning the original owner didn't perform the break-in procedure, at all. and then proceeded to modify it. That's just dangerous to the longevity of the rear end, driveshaft and transmission.
Everything about this vehicle is one red flag after another. This is why I called it a BS car. Builds like this are great for inexpensive cars like Mustangs. If you roll the dice and come up short, you lose 20-30 grand. But, for 100 grand, someone is buying a car that's not been broken in properly, modified, then left to sit stagnant for the better part of 2 years. The drivetrain in the Redeye costs more to replace than the MSRP of a basic Mustang GT. This is what's called a high-risk vehicle, both mechanically and financially.
While I recognize that the OP is in this car for way too much, I don't believe that the buyer can be expected to pay for his oversight. Just go take a look at the auction values of modded, P1400 2020-2021 Redeyes. Those things don't bring close to MSRP (typically 10-15k under). The worst place to try and sell this car is to a forum full of Mopar/Hellcat specialists who know exactly what the score is on this car. IMO, to get to the break-even point on resale, this is the type of car that will have to sit on a lot a good long while until some 30-something with more money than sense just has to have a Hellcat and isn't of the mind to ask many questions about it. If it were me selling the car, I'd not hide anything, but I wouldn't advertise it as modified and I wouldn't breathe a word about it having 900whp. If they asked, I'd be honest and tell them... but I know full well that the person who pops on the car is going to be the person who buys it either sight unseen or who doesn't know anything about a Redeye. That's the demo for this car... not a forum of people who will spend days asking questions, or someone like me who would send specialists on-site to validate it from top to bottom.