I cannot advise re that company, not being familiar with them BUT I did have a very bad experience with a very well known purveyor of Brittbikes here in the US so I advise caution with buying without being able to physically examine/test a possible purchase.
In my case, I was advised that the '74 Commando Roadster was "ready to be ridden out the door across country. It's in perfect mechanical condition and the engine was recently overhauled." I accepted that and bought the bike over the phone. It was delivered promptly and in excellent cosmetic condition. From there on - nothing but a mess. Among the things I discovered:
1. No oil in the front forks - a tar-like substance which may once have been oil in one fork and only rust in the other.
2. Bike wouldn't start - pale yellow spark at plugs - electrical connections corroded/rusted. Clearly, it couldn't have been started and ridden "out the door."
3. One rear shock had the rod separated from the piston internally so no shock absorbing at all on one side.
4. Once started, LOTS of oil smoke from exhaust. Later discovered rocker spindles were installed backwards, allowing excess oil into the rocker boxes.
5. Slide on one of the Amals would not consistently return to idle position due to warped carb body. All carb mating surfaces on both carbs were badly warped due to extreme over-tightening of the fasteners.
6. Vacuum leaks while running due to open cracks in the carb balance hose.
These are just the things that I recall off the top of my head; there were more. Basically the bike was totally unsafe and unrideable (Heck, un-startable) despite claims of its superb mechanical condition. Obviously, it depends on what you expect. If you are buying a known basket case or bike that you KNOW will require restoring and is priced accordingly, that's fine. But if you are buying/paying for what you expect to be a bike you can "immediately ride across country," be careful with sight unseen!
It took a lot of work and several thousand dollars to make this alleged "ready to ride" Norton ready (and safe) to ride.