Further to https://tickett.wordpress.com/2014/12/04/doh-it-doesnt-fit/
I was unable to find a replacement heatsink which would allow the Broadcom NIC to fit. I did however manage to replace the standard heatsink screws with these (12mm M3). I bought a pack of 100 from RS for a mere £1.52 (rs stock no 553-403);
You can see how much smaller they are than the stock screws;
Here it is fitted;
And the card fit;
Note that I added a bit of electrical tape to the end of the NIC to make 100% sure none of the components will short. As well as slotting a small sheet of paper between the card and the motherboard.