Ann: Notice of Annual General Meeting/Proxy Form, page-41

"but roughly what level of investment would be required to complete the above trial $$$"

No precise idea. But definitely researchers have done similar projects in the US in the past and I presume the money came from grants because there was no immediate likelihood of commercialisation of ebmryological tissue implants. It gets a lot cheaper if wealthy research neuro-surgeons donate their time?

But I would guess they would need USD $10 to $20m up front. Somewhere in that ball park. Clinical trials don't get approved unless you can show you actually have the funds to complete the trial. A philanthropist in the US or some kind of deal? First step would be to find an enthusiastic investigator with enough street cred to get financial backers or research institute interested. I would guess that's what they're trying to do now. The previous plan was gold if they could have pulled it off. But just about everything that could have gone wrong did. Kind of a medical version of WW2 operation Market Garden, "A Bridge Too Far"...