Glue question

I am working on an old clock for a clock restorer, I am just replacing broken parts and some veneer, he will be doing the finishing. There is some sculpted plaster that I need to re-adhere and need advise on what adhesive would be best, picture will show missing piece.

thankyou in advance

Tom, this question has Dave Hawksford written all over it

You are correct Glenn, HEY DAVE!!!