Many thanks to several people who have kindly offered to help. The generosity of fellow members of the caving community is really quite amazing.
I think we may now have a plan (via the person who has PM'd SamT). If anything stops that working, we'll liaise with someone else who kindly offered to help above.
None of this would really be possible without the help of this forum so, as I've said,
thank you to those who put in the time to run it.