I first had to fit the original pipes to the top of the new castings - the key point being that the outer shells' mounting holes also had to line up with the corresponding holes in the pipes. The pipes also had to end up being the same height as the originals.
Luck was on my side. Until this moment, I hadn't realised that the pipes were bored out at the lower end so that there was a lip to support the pipes at the correct height (assuming the new castings were the same height as the originals - which they were!).
|Supporting lip at lower end of pipe|
|Pipes on casting (ignore the bolt heads)|
Outer shell mounting holes are highlighted
|Pipes line up with outer shell fixing holes|
|Tapping the castings|
|Corrosion around an outer shell upper fixing hole|
|Corrosion around outer shell lower fixing holes|
|Outer shell upper fixing hole repaired|
|Outer shell lower fixing holes repaired|