Story so far
Thanks to the people who have put their hands up so far, it would certainly seem possible to get something going on the basis of this interest, especially as the provisional orders include multiple rolls.
I can see the argument for going to Delta, but unfortunately it's so minority in usage relative to the standard emulsions, that it would limit the take-up and probably kill the whole thing. If FP4/HP5 could be established in 70mm, the Delta emulsions could follow.
Having checked with Hewes today, the 70mm spirals are available in both capacities from stock, and are round the £50 mark, which doesn't seem too bad for a large piece of S/S kit like that. Hewes don't supply any sort of deep tank cage, but recommend using a central rod for agitation in a deep tank.
One downside is that all potential orders so far seem to be from the US, which means Silverprint is in the wrong continent to be co-ordinating this. If a specialist store in the US is interested, I expect they can get the same deal. However we can send, shipping costs by surface mail from the UK should not be onerous, but does anyone have anything definitive for the X-ray risk for film on surface mail from UK to US?