Yep, both Pelt Nova's and yes, you can trace them very closely.
LINK :: https://www.allaboutmarbles.com/viewtopic.php?f=5&t=36325&p=273100&hilit=Peltier+Nova+run#p273100
Wow, do you know if they were just regular glass, irradiated, coated ?? Sounds very interesting.
I found this, is does say NASA used them in space balloons, guess there's a whole lot to it that was unknown to me, good post !!
First 2 turquoise ones are Imperial
Second looks Akro
Third MK
Fourth Chinese torch marble
I should know this one but my mind isn't up to speed yet today
Heard of a lot of marbles made for all kinds different industrial use, paint spray can rattlers etc...... Can't say I ever heard of Tracor specifically ??