I needed a slightly uncommon remote key and standard transponder key for a 1997 Mercedes and Andras at Car Keys Banbury managed to supply both with a very quick mail order turnaround. I posted my key on a Monday afternoon and had the new keys back by the following Thursday morning. There's no guarantee he'll be able to do the key you want, but he'll be my first choice from now on.
https://www.carkeysbanbury.co.uk/contact-us/