Missing Master Key

[alice's dad]

My wife has got a 97 2.4 Previa which is generally great but has a couple of problems. They aren't directly related except...

We only have one key. Another key ordered from the dealer won't code because the one we have isn't the master. Is there a way around this or do we need a new ecu and keys? (Is is possible to retrofit from a scrapped motor? Is the system the same as on any other Toyota. We've been quoted £500 plus labour :o by our local dealer to fix it.)

On top of that, the remote central locking has packed up. Tried new batteries, tried being well away from the car and holding both buttons to reset the remote. No joy. Is this related? If we fix this (also really expensive from Toyota) will it mess up anything to do with the key coding?

Apologies for so many questions in one post, but they seemed connected!

Any suggestions gratefully received!

Thanks,

Rich