Kasper wrote:...some good solders skills and you can repair that...the difficulty is making a straight new hole to fit the pin. Very difficult place to drill.
I wouldn't solder and then drill a hole from the inside. Like you said, it would be difficult to drill a straight hole, unless you have a dentist-type drill that can drill at a 90 degree angle. I would rather place the pin (extending slightly like the one on the right), and then solder the pin inside the cavity. You can then file and polish afterwards.
OR If that's not possible, solder the cavity, file and polish, then drill from the outside. Re-attach the band, insert the pin (long enough to extend to the inside and attach the link), re-solder, re-file and polish on the outside.
A lot of work, but it is possible.