Until there is some air in the tubes there is no way to know how bad it is.
And actually, from the single image it doesn't look that bad with regard to the hard bits.
If it's cheap enough, just add a new set of tubes and build it how you want it rather than how the manufacturer thinks it should be or previous owner wanted it.
looks like a good fun couple of months work in the evenings/weekends to me.
The figure I had in mind was £500 based on the engine being £1k up together and serviced if it’s ok. Nose cone has fully
Fallen off, transom come away etc etc!
theoretically repairable - but might be like painting the forth bridge* especially if you dont have temp and humidity controlled facilities, but... I'd have thought Zapcat tubes were readily available as replacements?
* I am aware the forth bridge now has an epoxy coating which means the simile is technically no longer valid.