Here we see the inset panel now reinstalled in it's final position.
To avoid buckling due to the heat of welding the panel is tacked in place and will in due course (as my solicitor would say) be carefully continuously welded in short sections.
Due to the way the light reflects off it, the scoring looks quite prominent here against the dull sheet.
However it is only about 0.5 - 0.75 mm deep and after shot blasting and several coats of paint* will be much more subtle.
(* by that fine craftsman, John Sanderson working next door)
Internal view of the installed inset panel.
The panel is stiffened with two 5 x 25 x 50 mm channel sections.