Really you'd be better off starting your own thread.
I guess being an estate yours is two button as opposed to the later saloons some of which had a three button, for the keyless boot. The key, immobiliser chip and the CL remote plug together into one unit.
Martin Imber, also a member on here, offers a repair service for these keys. £12 to fix the battery holder. Or £17 to do the buttons and shell as well. Order through
his website here.
However expect to be without the key for a few days. Also your superglue might be an issue, ask him.
Replacement remote circuits are readily available as are the shells and the buttons and blank ID40 chips. The battery holder is not so easy. However you would need access to a Tech-2 to program the new remote to the car. And also for the immobiliser chip if you replace that.
So repair/refurb of your existing key is very good value. Way less than the cost of a new key and programming by an auto-locksmith, assuming they are competent, which is where this topic started.