You may want to check Old Frame (https://www.mtgoldframe.com/), which is a format I invented that tries to bring us back to those days.
We started by using almost the original banned and restricted list, except for obviously needed changes like restricting Flash and Time Vault as we play with current rules.
Then, we made some extra changes, like restricting Merchant Scroll and unrestricting cards like Entomb.
We also added the rest of the Old Frame sets that weren't allowed those days, which are Starter 1999 and the 3 Portal sets.
It may not be 100% what Vintage looked like those days, but I think all these changes make the format better. Using current rules and errata also makes things easier for those that play other formats.
We run a bimonthly online league and there's also a live league in Madrid. You can join our Facebook, Discord and Whatsapp group if you want to learn more.