That's a very interesting little thread relating to the No9 variants Mary's dad. Thanks. But I don't think that there'd be a need to re-weld and re-finish the front grip-screw hole if a UZI bayonet blade was to be utilised in a SA No9 bayonet. The hole would just remain hidden and redundant - as are the 'spare' holes in a No5 and L1A1 blade.
Who'd have thought that there was so much written about the humble No9 bayonet!