I've found companies that sell Ensolite (or like) foam, although I haven't found any that sell it with the off-white vinyl "skin" that's on the inside of the Boler
. That said, it is paintable.
I spoke with IR Specialty Foam, in Washington, when I was thinking about buying a "bare" trailer. Another member who re-insulated an entire Boler
used the foam from them. It's black, and comes in varying densities and thicknesses (I believe the original Boler is 3/16" although I'm not sure of the density).
If you do find any with the "white" vinyl finished side, could you please report back to the board? It would be nice to know a source for that.
PS You can find IR Specialy Foam and another source under "Ensolite" (one trade name) in the "Helpful Links" area to the left.