EDIT: Oops, I see now you can get KLM for £263 return for both of you.

Are you interested in spending Avios?

There is availability for Golds when I search (and I'd say for all); both days are off-peak. Total cost per person 16,000 + £70.

Lets say you have no Avios and you have to buy them at around 1.2p, I make this £262 for the return journey ABZ-LHR-ZRH per person, including a bag and free seat selection.

It can be booked using the website if you don't mind two hours at LHR to connect. Otherwise call.