Looks like Sticky's manual for Vespa wide-frames has come out. His books are required reading for Lambretta owners… I would suspect this one is well done also.

https://www.stickyfeatures.co.uk/store/c1/Featured_Products.html?fbclid=IwAR0DHvML8V-VYyO3vtzCAZW7wtJYK4SBt4EpxMwykS83l7NIj6bbAzRx-4g