Refurb an old yank junker ? Pie in the sky. I was involved with a study on one of these for another purpose and it failed on ££££. The best option was to start with a fresh barge and built on it what you wanted.
As for the London heliport question. The most obvious answer to mitigate any noise, would be to combine it with the city airport. 'Simply' fill in part of the basin to the North and there you have it. Some usefull pads, more parking for all, ATC already in place, light rail link and fixed wing connections. Current city owners (forgot who bought it) would be laughing all the way to the bank (unless it's Barclays or RBS, as there the next for a run ?) what would it all cost £ 100 mil tops. Then they can re value and re finance the complete site and pocked at least that as a bonus. and I'll take a 1% commision thanks
