I think you're right about PCP, they aren't as dead as they once looked.

But it isn't really a huge part of the overall corporation.

Sure, you could make a case for adjusting book for PCP back up to what it was, then using a traditional multiple. The problem is, both good and bad things have happened. There are real problems at BHE, which is far far larger. It's entirely possible that the true intrinsic value of BHE is a third less than what it appeared a few years ago.

One sign of that complication:
If I estimate value based on earnings of things other than investments, or a conservative multiple of book for things other than investments, the book based metric is a fair bit higher even when using a book multiple that used to make the two match. Phrased another way, return on [non investment] book assets seems to have fallen.

Jim