I trashed the speakers I had mounted on the back of the firewall and mounted new 3 way speakers on the stainless shelf behind the seat. Speakers
I wasn't happy with the tin can echo from the old ones caused by both the quality of the speakers and the location (without any inclosure). I had 2nd skin insulation under the shelf and the sound is 100 times better now. I drove it out to the trim shop to have carpet and headliner installed. Now 44 miles on odometer. I don't remember my 51 back in 69 riding so rough but I guess when you're only 26 your rear is numb.

~Jim