-JdK- Mick in the UK sent these pics of a set of unusual Norton girders containing anchor points for brake plates on both sides. We have seen home made jobs like this before but this set-up looks either original or if not, then very professionally done.
-Richard- These forks look like they were made at the Norton factory. Apart from the second brake fitting these are the standard WD 16H type. As a guess it is possible this conversion was done by Bob Collier who was Norton's "jack of all trades" and worked in the experimental shop post-war, and this type of thing would have been typical of the mods he would have made, perhaps for a trials or racing sidecar outfit. It will be interesting if any website viewers know more.