So to conclude to this post. For want of a cheap plastic replacement part, I’ve had to fashion my own repair.
Grivel will not sell the part so either I send the crampon to them in Italy for repair (70bucks) or claim the warranty from the vendor (somehow, with no receipt) and there’s been no response at all from the Mountain Boot Company – apparently the UK distributor. I've not got the will to grovel further to Grivel so have had to develop a more robust solution:
https://photos.app.goo.gl/Aaud8vvJEYEaiLyA6
Dyneema through the old restrainer lugs doesn’t seem like it will hold up well to abrasion.
So the toe bail hole locations have been copied from my G14’s [4.5mm hole, 3mm bit to oval] and the same toe restraint from my G14’s is used.
I’ll try them out like this and then probably chop off the lugs to match the G14’s
Then I’ll do the other crampon too.
Obviously I wouldn’t recommend these plastic toe restraints on Grivel crampons. Or their customer service.
Mine failed while walking – never mind the PITA repair - others might be unlucky enough to lose a crampon while leading.