The foam in all original ones are gone by now - there’s a suitable replacement available at Home Depot for $3 available - cut it into 0.875 lengths put it in place you will have 8 feet left.@pbnaudio I used weather-stripping to replace mine — is that what you mean? It's the foam-with-adhesive for sealing windows, doors, etc.* I had 4 or 5 rolls already, various sizes — one of them seemed the right width and thickness (they compress a bit, so thickness matters — too much compression, they become like hard rubber and no longer isolate; too little, and they do nothing at all).
But they also come in different densities, from very spongy to quite firm.
Which density, width, thickness do you recommend Peter? It seems many of the DP-80s in this thread may need it, and it's a fairly easy DIY.
* Ironically, I never used any of them for insulation. Only for Audio; one of the many useful 'tweaks' at your local hardware.