I am adding some links to web sites about Lambert and Viscount bikes that I have found useful and interesting. The list of links is on the right. I will continue to add to this.
The resource that people often find first is that on the site of the late and greatly missed Sheldon Brown, although the article is by Tim McNamara with SB. There is some useful basic information, particularly about dealing with bottom bracket problems. However it is written I think from a professional bike mechanic's point of view and an American one at that and it tends to accentuate perceived negative aspects of the bikes. There are some errors too. It has just been pointed out to me (thanks Steve) that I followed the Sheldon Brown article in making the basic error of saying that Yamaha took over the whole Trusty / Viscount company; whereas they only took on the US dealership.
For some uncontentious nice pictures of early Lamberts, see Classic Rendezvous.
I have previously mentioned the useful information on the CTC forum. Bear in mind that posts are being added all the time, so you might need to search a bit for what you need to know.
Out for a gentle ride on my Lambert (complete with type three death forks) today I managed to collide with a kerb. The forks survived but my inner tube did not.