Custom Blade Identification

[Gordon10]

[attachment=37026][attachment=37027][attachment=37024][attachment=37025][attachment=37024][attachment=37025][attachment=37024][attachment=37024][attachment=37024]I bought a Norris Panel Plane about 18-19 yrs ago that came with the original blade plus a special blade. I lost the correspondence with the seller, describing the blade. As I remember, the blade maker inserted some different material into the blade back, trying to achieve anti-chatter or something else. He said it would cost $1,000 to make that blade and he would never do it again. Sounds pretty wild. I can see someone definitely put some effort into this blade. I've attached some photos and was wondering if anyone recognized the maker's mark or knew anything about this experiment?

The material seems to be slightly different than the blade, but forged together, maybe 1/2 thickness.

Thanks,
Gordon10

[AHill]

Did you buy it from a seller in the UK or a seller in the US?

[iclark]

Only attachments 26 and 27 worked

none of the 4 attempts of attaching 24 or the 2 for 25 worked.

because of the image sizes, you may need to put the missing images into a 2nd post.

Whoever the maker was, he had a problem with the piece that he welded in having a much larger coefficient of thermal expansion than the rest of the blade. My guess is that that was the source of the breaks in the welded piece.