Frame KS 1198
G'box G6 H46
Engine, gearbox and maybe forks are OK for the year but all in that Ariel twin frame.
IMHO, unless the overstamping has been really badly done there's no way you'll establish the original identity of the frame and it's clearly wrong for the engine/gearbox. It would be possible to say where the engine and gearbox came from - presuming they belong together - but with an unidentifiable frame there's not much pedigree.
The 'new' frame number for a 1954 swing-arm can be tracked to what it was on when it left the factory but it clearly doesn't belong with anything on the bike - not even the current registration number, which is from an age-related stack (again as Will noted).
Clearly whichever local vehicle registration officer inspected the bike in 1984 didn't know anything about Ariels!
'55 Huntmaster, '56 VH, ' 51 VH, '80 R100RT, '00 Sprint ST (but all those Ariel parts can only make one running bike...)