I would suggest no, an extra Engine or Repair sailor would be more beneficial. If my memory serves me right the restore stat stacks and could just be compensated coming from your engine or repair sailors.

That's how I understand it, and I could be wrong.

Go for an exptra Engine or Repair. :)

No, restorer is not useful.  Maybe in blizz and at low level when SD is low.  But they are not used once your sailors and ships reach higher level.