Let me start by saying I am generally happy with my stock shocks and don't really require the sporty versions etc. On my last check the mechanic told me there is a slight leak / misting on one of the shocks. I wanted to get it replaced but since it is electronically controlled they cost in the region of £320 each.

 

This lead me down the path of seeing if my current ones could be refurbished. Found this company in poland (nagengast) that does it for 145 euros each (seems reasonable) however thanks to brexit you can add ridiculous charges for customs etc. My question is, does anyone know of UK companies that do a similar job? Is it worth the hassle. Has anyone got them done before or would you rather just buy brand new?

I haven't heard of shocks being refurbished in years. Unless they're going to use heavier oil you'll be back to the horrible wallowy yokes it started life with. I'd bite the bullet and get the new ones. 

A report of  'slight misting' is not unusual. as common as being told the brakes are 80% worn when they are not even 20% worn.

  Slight misting being reported year after year is not unusual either even when the first report is no pretty new cars. 

 

If they need replacing best get ones that have a warranty and if there are issues can be dealt with using the Warranty with the supplier.

I mean, we get shocks refurbished for work as there is no other option as they were custom made originally. But seen as you can still buy them, id just buy new.