Consider it done!
Again, I'm not sure whether I should be creating a new thread for this, but what the heck

Here's how the ESM-2s looks sans-woofer surrounds:

Here's the very technical part of the refoaming process using my medium-density polymer low-tension clamps (aka clothes pegs). The foam surround has already been glued to the cone in these pics. I used the clothes pegs to help keep the woofer surround in position after making minor adjustments to ensure the woofers were perfectly centred. I would then remove a few pegs, glue that section of the surround to the frame, replace the pegs, remove some adjacent pegs, and repeat the process:

And the finished result (they still need a good clean overall, and the camera flash reveals EVERY little mark/fault:

To give you a sense of the size of the speakers, the woofers are 8" (so they are floorstanding speakers rather than smaller bookshelf speakers).
I will also be refreshing the black grilles with some fresh grille cloth shortly. Once this is completed they will present VERY nicely for 22 year old speakers (as well as sounding great for a total investment of less than $AUD 50 incluing the surrounds, glue and grille cloth, and the stack of Onkyo gear that came with the speakers).
My Sansui AU-417 has the pleasure of driving the ESM-2s (it's in great condition for a 30 year old amplifier):