Not sure if the gap is that big. The Helson can have another £100+ added to it by the time it is through customs and you can get the Longines a few hundred cheaper. Still £500 though, would be interesting to see how the finish matched up. My Helson is the cheaper end of the scale there.
So is the Helson underpriced at £560 or the Longines overpriced at £1,460?
They both have ETA 2824 on the inside...
Well, Longines fit their own branded rotor weight on the 2824 and call it a L633 instead.