Just tell the wife the ones on ur bike r done mate & u need to replace them for the MOT Hope my missus doesn't read this or I'm done for
I think u can get the lights from around £30 from china. I ended up paying £45 for mine from the uk for a little piece of mind. They fit perfectly.
I have a quality one of them that I don't use anymore . Could be persuaded to part with it if you cross my palm with silver
Got mine second hand from eBay in perfect condition .. half price is all I payed .. just keep yur eyes peeled