I recall you mentioning him quartering the GMH before. It adds weight to the old posts that he deleted and indicate the proposed method to the overall intention. Inserting MR keyslots into a GMH would widen the helmet straight off the bat. The keyslots on the GMH and the KT are too narrow. I suspect this could be a result of the first cut repair. The other thing I noticed with both my FPH2s was that the rear back panels had a sort of trapezoid quality to them making them look like extra material had been inserted there. Whatever the case I think the dent points to PP2 and the keyslots to MR. If I were doing a family tree, which I'm not, then I'd have the FPH2 linked to both the PP2 and PP3 by virtue of those points alone. The keyslots were obvious on the first one I owned, the ROTJ version, which I had in 2015 or 2016. I owned the ESB version at the tail end of 2018 I think. The dent screamed PP2 at me the second it came out of the box; it had considerably less work done to it than the ROTJ version. It's not just the overall circumference shape but the depth as well.
As you say, only he would know. I'd happily be proved wrong to know the truth but I'd have to see the workings to believe it and that doesn't seem very likely. Until that happens the GMH/MR theory seems perfectly plausible.
