Rear bulkhead and spring hangers were mostly replaced with new parts, followed by a pair of 1/2 floor pans. Then boot floor.

I think this is a later Sprite part since it has recesses for the 1/2 elliptical springs trailing ends,  I don't know what the original looked like since it didn't come with the car!

Some of the panels waiting for fitting.
The rear wing was delivered by post just as seen herewith no additional packaging, the address label can be seen still attached.

Recommendations for anyone starting a similar project (in no particular order):

Make detailed drawings of panels prior to removing them, in particular the positions of any holes, such as the locating holes for the accelerator  (gas!) peddle.

Don't be tempted to leave any traces of rust, you will regret it!

Don't trust the chemical rust inhibitors to passivate rust.  The only proprietry chemical  I have faith in is Jenolite, this does desolve rust, but may take many applications (possibly 20 or more) with wire brushing before  the rust is fully etched out of any pores.

Take lots of photos, especially of wiring and brake pipe routing.

Keep everything straight and square,  keep checking diagonals and use a long spirit level.

Use temporary angle iron braces to prevent the car from distorting as sections are removed.