Fork brace will be after market. Few - if any - bikes from that era came with one standard. The other thing is a chain type wheel lock. Most of the chain fits inside a plastic container bolted to the frame and one end of the lock attaches to a little tab welded to the frame - has to be undone with the key so it can't be nicked. The RH parts list shows it:
The chain lock is part 32 and the plastic case for it is part 33.
As for the Honda being cheaper....well, it is a Honda after all
There was a Honda ad campaign in the early 70's for its motorcycles with the catch line:
'Honda's have got the get-up and go',
.....to which was unkindly added by some:
'yeh, if you've got the get-up to push 'em' [no offence intended by any of the above
]