It sounds like you want really contradictory things. On the one hand, staying with late 1980s 3ttt but wanting a hand position that was simply not how bikes were set up/riden then. These are optimized for the drops.
You can restore authentically or have a modern hand position. Both are fine, it's up to you, but you can't really have both. And it's not just about maintaining "authenticity" whatever that means. Bikes were just designed and fitted differently then. Keep in mind the whole bike as a system... Is your frame sized properly for the era? If you are showing too much seat post, then no it's not, and this is going to mean you cannot get your bars high enough to make the kind of riding position the bike was designed for comfortable.
Take a look at this, if you haven't seen it. He has bikes from earlier eras than yours in there too, but the point is basically--the height difference on a modern bike from saddle to hoods is far more extreme than the drop in the 1980s from the saddle to the drops themselves. Racers today hang out on the hoods, racers back then hung out in the drops.
https://bikeretrogrouch.blogspot.com...tions.html?m=1
I would say, get something like a Nitto Noodle bar. It also comes in 26.0mm clamp diameter, which is probably also a consideration for your stem. It can be set up with flatter extension but still looks classic. Yeah, it's not 3ttt, but the best choice I made on my early 1990s Bianchi was ditching the 3ttt bar and stem for Nitto. Authentic? i guess not. But unfortunately Italian authenticity from this era can also mean quality problems...
If you must stay Italian, expan you search to other manufacturers.