Thanks for the info! Much appreciated.That is a relabeled Yankee 354/Signal Stat 374. The only differences between the Yankee and Signal Stat are the dome shape. Yankee used a dome with a raised section on the top, the Signal Stat dome was flat across the top. By the way, either dome in good condition is hard to find. I'd say that's a real nice find you have there!
This dome is comparable to Federal Signal in strength and thicknessLooks like it led a sheltered life. Take good care of it, definitely do not damage that dome! I've not handled a Yankee dome, but my Signal Stat 374's dome (original and in excellent condition) seems thin and somewhat fragile compared to Dietz and Federal Signal domes.