Thanks Gilles, I was a bit afraid of that...
So, time to cut the crimp part of and pull the pipe out. You might just be able to see that it does have an O-ring to seal and inside the pipe the deformation due to the crimping is visible. So it still can't be pulled out and it might still seal, but not taking chances on this.
Your idea of welding on a standard fitting is a good one. I might try that with a local welder and probably go for a metric fitting (AN is not very popular here, although JIC is quite available) as suggested by the local hydraulics shop.
Otherwise I can buy some adapters from the bay, but these are expensive. There is a zinc plated steel set available with the same sealing (to the rack) as the originals. This combination I do like, but from the pictures you can already see that althought it'll fit AN, it does not conform to the standard (the rings from turning on the lathe are still visible on the sealing flange..). The other set uses double O-rings on the rack side, but do look a lot better quality wise (and are a little cheaper as a bonus).
Still, by far cheapest is to get them welded up. I have a double set (my car and the wreck) so can tolerate one going bad.