Once the new runs have been allowed to set in the adhesive, you need to apply the 3M NF30 (Milloxane) sealant. Although the can sent by Magnepan had a small brush applicator included I decided to use a 1" foam brush for applying the sealant. I applied two light coats, waiting 12 hours between each one. Light coats is the key here as you want the mylar to remain flexible.
While these were drying I decided to work on the crossover network. I had ordered some replacement capacitors as I assumed the existing ones would be dried out after 40 years and the values changed. Just for grins, after removing the caps, I tested them on my little component tester. Yep, confirmed; both capacitors were definitely way out of spec. They were supposed to be 12mfd and tested out as roughly 38mfd; definitely changing the bandwidth of the circuit.
I also decided to replace the "connection block" (nothing more than some connector rings riveted to the mounting plate) with something a bit more forgiving to work with. The old connections were made using silver solder due to the dissimilar metals being used (copper wires, copper connectors and aluminum wires). Although I was trained in the Navy on how to solder to aluminum with silver solder, the process is not easy and I'm far out of practice. All pieces to be soldered need to be scrupulously clean and heated to the right temperature. I made one attempt and decided on a better method. I substituted a standard screw terminal connection block. All wires/component wires were sanded clean, dipped in No-Ox-ID (to prevent oxidation/corrosion) and then placed into the block.
1st pic shows entire panel coated with Milloxane
2nd pic shows original crossover network with connections
3rd / 4th pic shows tested value of old capacitors
5th pic shows new connection block with new capacitor