A quick update: I was sufficiently worried about using two split links on the chain supplied to me by my local supplier, so I decided to buy another one from sprockets unlimited at the Stafford show today.
He recommended I try a 1/2x3/16 chain, which is something that some Scott owners have apparently been doing for a similar application.
I feel something of a guinea pig in this, but at £10 for an iwis chain, I thought it would be worth a go...
AOMCC Member Number 4068
1957 Ariel VH
1956 Ariel KH (LARGE project!)
2016 Honda CBR600RR