“The aptly named “Flatten It” device is designed to do exactly what its name suggests: flatten warped vinyl records. This isn’t some DIY hack; it’s a purpose-built machine that uses carefully controlled heat and pressure to restore your records to their original, pristine condition.”
Some things improve over time. I don’t ever recall seeing such a device back in the 1970s and 1980s when we all used vinyl records.
Nice to know there is a safe way of “tuning” your vinyl records. I still have all my old vinyl records (along with the player) and I certainly could have used this device back in the day. I loaned one record out to a friend, and she left it in her car, and the record buckled a bit. I had to throw that record away.
But this device is not at all cheap at US$850.
See https://www.howtogeek.com/this-machine-flattens-your-old-warped-vinyl-records