Thanks for the info!
I was going to get the correct size plastic bung and either leave it black, get them soft touch coated to match the handles and door pulls, or get them painted body colour. I’ve not decided yet.
There is a 3L on eBay that’s had electric windows retro fitted and I don’t think it looks too bad with the bungs in place.
I’ve already got some GTI door cards with switch cut outs to go into the car so no need to accommodate switches anywhere else.