How to: repair speakers with blown woofers

In college I bought a pair of Polk Monitor 5 speakers for $200.  They were probably built in 1981, which now makes them old enough to vote but not quite old enough to be elected U.S. President.  They were in my living room until a few years ago, and I still listen to them in my basement when I'm exercising.  Or at least I did until my cat puked in my amplifier (below) and blew them up.
I'd made the tactical error of placing my power amplifier on top of the preamplifier.  The power amp has vents and I wanted it to breathe freely.  Well, power amps are nice warm places for cats to lay, and cats occasionally get hairballs.  It must have scared the crap out of him when the caughed one up and the speakers made a mighty BLATT.  It blew a fuse in the amp and toasted one of the woofer voicecoils.  I popped another fuse in the amp (and vacuumed the hair out of it!) and it worked fine.  But the speakers needed new woofers.

Polk sold this woofer, the MW6500, to technicians for many years to make repairs.  Then they made a near-equivalent replacement, the MW6502, for even longer - people were still buying them in 2008.  But after 30 years it's not reasonable to expect a company to continue to offer replacement parts.  They recommended I contact the good folks at Madisound for a substitute.  We settled on the house brand Madisound 6102 woofer (the left pair below) as the only one that would fit the highly constrained front panel of the speaker.  It sure does fit - even the screw holes are in the same places.
What does the inside of a speaker look like?  CLOUDS!
The white stuff is a fibrous filler often put in speakers to reduce internal echoes.  And the larger cone at the bottom isn't a woofer, it's called a "passive radiator".  No power gets delivered to it.  As you can see, I soldered the leadwires to the new woofers and...
THEY WORK!  They even sound pretty decent!  OK, I haven't run them with a sound level meter to make sure the tonal balance is right, but this is not bad for $50 worth of parts!