Of course, yes. I should have had a look for it there.
Problem though. Adding the adjusted line there doesn't work. The code hint (see image below) suggests an issue with the double quotes (tried the _QQ_ workaround but doesn't fix it). Interestingly, the exact same code works if I remove the override and go back to adjusting/uploading the original file. If I then look at the replaced code through Display->Views (what it now thinks is its original) the same code hint is there but the value shows correctly for a new product. Something to do with any override being ignored owing to the code hint issue perhaps?
I've left the 'amended original' in place for now as it works well. Would be great if the override worked; but not a major problem in the scheme of things.