I could buy another S5 I guess
I do not think so.
Or get 2 x A570IS as Gregg suggested ?
Yes.
I do have a broken S2IS that I am slowly dismantling to see if the shutter is stuck ?
It is very unlikely the shutter is stuck.
It is normally a tiny, pivoted, blackened steel shim that is attracted to one of two electromagnetics.
A brief pulse moves vein to the electromagnetic and a tiny magnet keeps it in that position until a pulse energises the other electromagnet.
More likely, the zoom is distorted and sticks or the lens-protection blades are sticking.