You can always put them up in the forsale thread here or in your sig. I'm sure one of the guys/gals here will buy them....maybe even myself.
Modolo conventional brake levers were considered to be the best finished and anatomic in their day. The hand-fitted hoods especially.
The Kronos aero levers were 'plastic'. They didn't function very well. These look more towards function than fashion. They may work just as well as most aero levers. It's just the shelf-life of the delrin plastic. Will it snap unexpectedly one day? Maybe. If they're NOS stored all these decades in a box wrapped from UV and ozone, I'd deem them safe enough to use.

As Randyjawa pointed out, Modolo made a lot of pretty product, unfortunately their engineering was lacking...Kronos line of plastic parts that eventually snapped, their unique stem line that unexpectedly sheared off and causing a horrific accident, thus forcing a recall. Some of their bars also cracked due to being too thin. But style-wise, they were on top of the game.