There are lots of parts for the Heavy Bolters as you can see above, read on to see the wing bolters come together.
After I'd cut off all the excess and and cleaned up the parts, I realised the parts didn't fit (no change there then) I had to drill the hole slightly bigger. It's a simple fix with a dremel.
Next, I had to clean up the barrels of the heavy bolters using a round file. After that they came together really easily.
Here you can see the wing heavy bolters in place. Next update I'll show the work on the front sponson bolters.