Hi Ian.
Also get you mechanic to check the Y connection onto the head, they go brittle and can leak, how mush coolant are you losing? are the coolant cap O-rings ok, how much is in the coolant tank.
1
2
3
4
5
6
coolant level, do not over fill as you will get no expansion, and lose coolant through the cap.
7
8
check the O-rings on the cap are not flat, if so replace
9
10
I would suspect these above more so than the metal pipes you have concern for.