If I was a betting man, I'd be thinking to myself that if these methods were surefire methods of mechanically re-warping or straightening expensive fore-ends, then we'd have been taught it. Especially as we were taught to save them in other even more time consuming ways, such as complicated patching etc etc. That's not to say it ain't going to un-warp a fore-end of course. Maybe the criteria that was set was a bit more severe when the trials people investigated this sort of thing. Cold and hot temperature tests, dry and wet heat trials and all that stuff......
Just me thinking out aloud. But all power to your elbow for trying and getting it right I say.
If I had a LB No4 Mk2, I'd have kept it regardless of the fore-end - due to its rarity Richard. (Just being flippant on this fairly warm Monday afternoon)