I cant see any reason why the owners friends cannot buy a small share - and I believe that there are CAA guidelines on the minimum capital share allowable(5%??) - and operate it from the owners home.
This would be an identical arrangement to the more common farm strip fixed wing syndicate, ie the owner of the farm strip/ member of the syndicate is entitled to charge the other members hangarage.
Selling block hours immediately renders it a Hire and Reward arrangement, with all the insurance, HMRC and PT CofA implications.
If in the same position I would continue to operate it from home but sell shares in it. If the owner bases it at an airfield, a major benefit of the heli v fixed wing is lost, something the major shareholder wouldn't want?
Putting my business head on, a share in a total flying operation, ie an insured, hangared aircraft, is worth more than the percentage value of the airframe. So, if the interest really is there from other locally based heli pilots, the owner might just be able to sell, say, three x one-quarter shares for the current hull value and have a free or cheaper one himself, whilst continue to enjoy the benefits of a machine at home.
I would caution against a cash in the hand deal because the insurers will very likely find out in the event of a claim and won't pay out.
Putting my jealous head on I cannot imagine letting anybody else fly my machine. Unlike a fixed wing, it is possible to cause some very expensive damage on start-up/ overspeeds etc.
Nobody looks after an aircraft better than the person who paid all the money for it. Sell 5% of it to somebody and they will very likely only acquire a commensurate level of 'ownership'.
Keep us posted.