Well, it looks like I've figured out posting photos - sorry about what that first post used to look like.

I'm now 80% through refoaming the woofers.  This is not rocket science.  I know - I have a BSE in aerospace engineering (Michigan, '00).  🤒  Photos posted when both are set.

Lessons learned (so far):

1) There is definitely a learning curve.  I would say my technique was at least 50% better on the second woofer (so far), if not 75%.  I think by a fourth woofer, technique would be fairly accomplished.

2) Shimming, and therefore replacing a dust cap, has got to be done.  I don't know how you can consider refoaming without shimming.  No offense intended to those who don't/haven't in the past.

3)

So priority one was refoaming the woofers.  If that doesn't work, what's the point of doing anything else?

Here are both S40 woofers a few days after I adopted them.  

And here's the second one refoamed.  It actually looks better in the photo than it does in real life.  I'm not going to bother posting a photo of the first one I did.  See learning curve comment in post #2.

If you look at the surround, you may notice what looks like eight small bumps spaced equally around the woofer.  That's where there are small holes (screw?) in the metal basket.  (You can see said holes in the photo above.)  I could have avoided this by trimming 3 mm all the way around the surround (which would have also "matched" the original), but that would have left only 3-4 mm of contact area.  I guess I could have made cutouts for the (screw?) holes.  Another lesson learned.

The new dust cap is an almost felt-like paper, a bit different and certainly more mass than the original which was a slightly translucent, stiff, I don't know, cloth maybe?  But it was easy off for shimming, and easy back on and looks fine.

Neither refoamed woofer will win a beauty contest, but both woofers are done.  🙂  Took about 4 hours, but that was taking care of my kids and hosting an exterminator for awhile.  Actual work was maybe an hour, most of the time you're waiting for adhesive to set.  I will let the adhesive set overnight then do some listening to them tomorrow to see if I should proceed with the rest of the project.

I know there will likely be a break-in period, so I won't trash them if they don't sound pleasing right away.

Next report after listening.

Both woofers pass a quick and dirty Do I Still Work? test.  I hooked them up one at a time to my desk top system and played some white noise, pink noise, test tones, and music.  They both appear to work as expected.  It's amazing how little low end is heard before mounting in a box.  Speaking of which, next test will be remounting into cabinet number 2 (which still has an intact crossover) and more listening to determine if the project is to continue.  So far, so good.

The photo is of woofer 2 during "testing."

Nice job - well done for having a go.

Thanks, Peter.

Woofer 2 has been remounted in Cabinet 2.  All is well in S40Land.  Listened to some mono Zeppelin (both electric and acoustic), and it sounds like a loudspeaker.  Need to put S40 1 back together and do some stereo listening as a pair.  But it looks like this project continues to be a go.

I have three more questions for Greater Beoworld (question 1 was whether the crossover is wired correctly).

2) What can be done to tone down the ugliness of the gouge on the top of this cabinet?

3) The back cabinet wall is a molded plastic.  Anyone have any experience cutting this material with a jig saw?  Since a previous owner pulled out the cables from the DIN plug I thought I'd Americanize the cabinet and put a banana plug terminal cap in them.  (Did the same to my S45-2s with excellent results, but the back cabinet wall of the S45-2 is particle board or MDF.  Oops - there I go horrifying most everyone and revealing myself to be a "modder" and not a "restorer.")

4) It would appear from the back of the cabinet these were intended for wall mounting.  True?

Anyway, you should be able to see both issues below.

The reassembled S40s are pictured below in my desk top system (replacing S45-2s) taking the Whole Lotta Love Test.  They received about a B-.

I'm gonna play the heck out of them over the next few days and then report back.

New capacitors arrived today from a guy in Michigan I used to buy parts from back in the 80's when I built a few pairs of speakers.

Solen.

Dude.  They are huge.