CAT A and B are legal to own.
An old thread I know but I am sure there are others who would benefit from my experience.
I made a simmilar mistake and assumed a declared writeoff I was buying would be a c or d. It turned out to be a Cat A!
I tracked down the insurance company and they insisted it was no mistake, but they also confirmed they had not actioned destruction, but declined to discuss this any further.
I also contacted the DVLA and VOSA, both were happy for the bike to be on the road and explained that they had no interest in the various categories of writoff that the insurance companies use and the bike had not been reported as a writeoff. I have 10 years worth of documents the DVLA had issued after the bike being written off!
The general system they operate under is that they are advised by the insurer when a vehicle is written off, they then flag the registration details. In the case of a car it needs to be checked by VOSA for confirmation of it's identity prior to DVLA issuing any new documents, V5c, MOT, Tax disc etc. DVLA and VOSA do not have any interest at this point in wether it might be safe to go back on the road. The only safty check would be subsequent MOT tests as per any older vehicle. As far as I can tell insurers may see no need to report a motorcycle to the DVLA (perhaps they never do) as there is no VOSA check required to remove the write off flag on them. Or it may be that the DVLA do not flag them when they are advised by the insurers. as there is no system for VOSA to check the vehicle afterwards. Definitly a gap in the system somewhere...........
It seems that the categories are guidelines for the insurers for dealing with the salvage vehicle, they have no binding effect on anyone else who subsequently deals with the vehicle.
For anyone who becomes the subsequent owner of a cat A or B the only issue is obtaining valid insurance, which if you declare it you can't!
I can only speculate on how a cat A (or B) escapes into the open market. My suspicion is that some insurers do not always follow their own industry procedures.
What I do now know is that there are some bikes out there which have a history that means that they should not have returned to the road, but having done so are perfectly legal.