The floor/bilge in the main body of the boat (i.e. not engine space under the back deck) has now been scraped/cleaned of residual bitumen, most of which had been dissolved by the leaked diesel... that's been painted with grey primer/undercoat, and bilge paint in the middle third, the bottom of the 'V'.

New flooring has gone in; simple inch-and-a-half battens, framed on each side, with long runners in the angle iron that runs longitudinally in the boat, supporting the flat centre section; here's a picture of work in progress:



I've ended up using glass fibre loft insulation under the outer boards; I'd semi-deliberatly but the battens at 16" spacing (3 gaps per 4' length of floor) to allow for this. At time of writing I've done the full length of the boat, bar the awkward front where it starts curving up into the prow.

I've started turning my attention to the outside of the boat; being moored on the outside of another, I had no towpath access to the side, so ran up the engine and took her over to the other side of the canal, and took out the windows:



This was back in my mooring, where I do at least have mains power; I could lean out of the window with the angle grinder, with a wire brush fitting...

After window removal and cleanup with a chisel, the sides were in this state:



Wire brushing out the loose stuff gave me clear confirmation of the horrible truth; Tortoise was once painted yellow:



(strata go from exisiting green, down to red oxide base).

Chiselling out raised paint to expose the rust underneath confirmed what I expected - the sides are reasonably sound, but there's some rust, some of which has gone right through under the eaves. I'm hoping to have a lebgth of new metal welded on the inside of that, giving me something solid to fill against; what treatment/filler I need to use, I'm not sure.