How much is a second hand bubble if you could get one
The Helicopter Museum at Weston-s-Mare tried to locate a bubble for their Sioux a few years back. The UK Sioux has a different bubble to other 47's. The museum ended up getting a standard 47 bubble and fitting that. Lots of gaps and I am certain that the CAA would not allow it to fly if the machine had been airworthy.
Long and short of it was, the only known spare bubble for the UK Sioux is held by the AAC as a replacement for the Historic Flight Sioux.
The museum could not locate a mould either, had they wished to get one made, so looks like this Sioux is destined to remain grounded.