Horn half works

[solidtyre]

My 53 reg Fabia has only half the horn working. I press one side on steering wheel there is sound, but not if I press the other side. I'm thinking it might be a MOT failure point. However, approaching eighty, I do not do much mileage and would not welcome the cost of buying another car.

 

Can someone advise what the likely parts and labour costs might be to properly repair or replace might be?

[TMB]

It will probably be the contacts inside the steering wheel. You have to take the airbag off to get to them.

[solidtyre]

I am a two left feet on my hands person! :(  The garage has got it working before, but maybe now I am tinking something more permanent could be needed, as the half that works is very tough too operated too.