I've never had the discutable pleasure of hearing TROWA cymbal by my own ears, but this is how one guy described 22" TROWA ride: "'Tis somethin' between cymbal and a church bell. You mustn't crash it, or it's gonna rip yer head off."
My guess for alloy is NS12.
Interesting thing about socialistic products like TROWA or Amati is their unbalanced quality, or how to say it. They were made from good materials but were manufactured so bad, or opposite-good design, good craftsmanship, horrible materials.
EDIT: Just found out this company was later renamed to Tacton, making copies of Sonor for East-bloc market.
[ame="http://www.youtube.com/watch?v=2aKPuluVEnM"]http://www.youtube.com/watch?v=2aKPuluVEnM[/ame]