In the past with similar frustrations I’ve found a suitable piece of cardboard, a cornflakes packet last time, and offered it up marking in your case, the lugs. Then punch holes through and see what’s what (making sure you keep it the right way round 
).
It’s blummin infuriating when simple stuff doesn’t ‘work’.
I also once, when lacking a suitable gromet, took the alternative ‘outside the box’ route, instead of a gromet in the frame, I slipped some suitable rubber hose on the plug itself then pushed it into the metal ‘hole’, it worked surprisingly well as a temporary measure.
Thanks for the advice. It’s another avenue to consider.
Hi Russ
I have 6 of these in stock. How many do you need?
Regards, Nik