After nearly 2 weeks of heavy play with the new soft dome tweeters from Rob at CSS, the brightness is totally resolved! Amazing! These are definitely an upgrade over 26-year-old aluminum dome tweeters.
@vair68robert- Thank you for the advice about soldering to the speaker connection. To reduce heating up the wire going to the voice coil, I applied alligator clamps on either side of the solder as heat sinks.
