No. 72 ‘Fenchurch’ successfully passed its steam test on 21 September 2022
Simon Blaker provides the following record of the boiler work undertaken:

The boiler was inspected when still in the frames during late summer 2019 at the request of the director Chris Hunford.

The firebox was seen to be in the later stages of its life with the early signs of fracturing of the firebox corners and welds.
We decided at this stage that the 1970s steel firebox would be changed for a new steel firebox to the Israel Newton designed firebox fitted to three other members of this class.
The use of this Lloyds approved design was agreed with the boiler inspector and the Boiler removed from the frames late 2019.
The boiler tubes were then removed and the boiler rotated onto its back using the workshop cranes.
The firebox was then removed to allow inspection of the backhead and throatplates, at this stage we decided to replace a ¾ section in the backhead and completely replace the throatplate.
The design of the new firebox meant that a new outer firebox wrapper was the easiest and most cost-effective choice.
Other defects and age meant that we finally ended up with:

New foundation ring, due to fractures and oversize holes.
New fire door ring, due to the old being the wrong size and upsetting the working of the firedoors.
New inner firebox, due to thickness, grooving and other defects.
New outer firebox wrapper, due to wastage, two old patch repairs and a different stay layout.
New throatplate, due to oversize stays, wastage and the early stages of fracturing from the stay holes.
New front tubeplate, due to a different tube layout and lamination of the lower section.
New 3/4 backhead, due to wastage and a different stay layout for the new firebox.
All new boiler stays.
A new section of boiler barrel in the form of a ‘D’ patch, due to localised piting.
New injector steam valve standpipes.
New whistle valve mounting pad.
New boiler tubes.
New regulator ‘J’ pipe.
New ashpan.
New smoke box with spark arrestor.
New smokebox main steam pipe.
In the course of the work we also made up our own crown stay taps, welded and machined in the works.