Think this was "fake news" Rob... I've also searched the Spanish internet for more information on the Civil War Brit Bikes, but they are all copying each other, inclusive (a lot of) obvious errors.
The original documents, if they still survive, will be hidden somewhere in the "Salamanca Papers". I have tried to have a look at these, but no luck so far...
I do not believe it is "fake" news. At least not on the Nortons.
The amount of MC's mentioned in the article was only 2 off from what I could find in the assy book pages we copied.
As we did not copy 100% of all pages it may wel be incomplete. A single entry on a page could easily have been missed.
I only found 10 entries with sidecars while the article claimed 40. The remaining 30 could have been added by Psalty before delivery.
Will see if my Spanish contact can do/find something.