It also seems that the Distributor for TA might have also been involved the bottom bracket being threaded is from what I have gathered very rare only a couple hundred bikes with that Some cognoscenti have suggested 200 and some more.
I found this on Bikelist archive
As I remember it (hah) the first Lamberts were sort of prototypes and had some sort of Ron Kitchings connection. I suppose the threaded BB is the telling difference. Some of the earliest ones are also branded Reg Harris. Apparently there were similar Ron Kitchings frames, probably built with 531. I guess the TA? arms on Lamberts are part of the connection because Ron Kit was the UK TA distributor.
This has been a widely discussed topic
Originally Posted by
sykerocker
The Lambert-made bicycles were sold as Lambert, Reg Harris and Viking. I've noticed that the headbadge on the OP's bike is almost exactly the same in design to the Viking badges in the link that Randyjawa provided. As the original Viking marque is listed as having gone out of production in 1967, so I'm wondering if the rights to the original company weren't bought out by the outfit that developed the Lambert. Given the latter's reputation, I can understand why an article on a classic British bicycle would be loathe to admit to the connection.