I had no problem reclaiming the VAT on a new R22, starting a brand new company to own the asset, but they did expect to see copies of all the documentation for the purchase and a copy of a lease contract I had agreed with a flying school to burn hours on it. Repayment was swift thereafter. I'm hoping to sell it and buy a different one using the same company, so the trading history of the same company should help.
It is very sensible to make a lease contract with someone around the time of purchase and arrange to burn some hours in the early months to make the VAT return numbers look good for a couple of quarters, including VAT on all your own flying (which applies indefinitely). If things don't work out thereafter (business is business), HMRC will find it harder to ask for their VAT back (and believe me they can do that...!).
The beauty is if you are in a position get your own companies to invoice your helicopter company for use of the machine, because that is when flying becomes cheap. All you need are links to several small companies who can make this possible and numerous good reasons to fly on business, then you're laughing.
However, it'll never be as cheap as renting from someone else - the old saying applies, "If it flies, floats or f***s, its cheaper to rent"!
BW