Shoei RF-1000 Helmet Liner Replacement?

Hi to everybody after a 13-year hiatus. Having kids really changes your hobby time. 😁

I pulled my old Shoei RF-1000 helmet out today, and the liner pads are pretty much disintegrated. Looking online, I can only seem to find RF-1100 liner replacements. Can anyone direct me to a good source where I could get a new liner for my old RF-1000? In guessing it's old enough I might just be out of luck, but I figured I'd ask here first.

Thanks!