I've tried to find the answer to this question, but I have drawn a blank.
The best people to ask would be either John Carpenter of Mistral Engineering in the UK, phone 020 8501 2161 (+44 20 8501 2161 from USA, I think?) who originally developed and marketed the Rita kits, or Dave Comeau:
http://atlanticgreen.com/ignition.htm in the US.
I don't know if it's of any help, but my Triumph Trident T160 had the 47270A box fitted when I bought it (it now has a Tri-Spark ignition).