[RossR]

I think any competent watchmaker could do the job. It’s not necessarily a vintage specialist job.

I’ve got one too. Nice watches. It came from Singapore in 1968 as well, and there is a bit of a story attached to it.

http://www.thewatchsite.com/21-japanese-watch-discussion-forum/174369-receipt-seiko-dx-6106-8040-a.html

I hope you get it fixed without too much trouble.