warren3200gt wrote:Where are they located?

Unfortunately USA but they do ship to UK
https://www.vintageconnections.com/pages/about-us

for the blocks, these are ideal
https://www.vintageconnections.com/prod ... 1774030145

if you remove the small grub screw from the steering lock you can drop it out and check that date code. If the same then the key number for that should be the same as seat lock

If you are interested, the L76 is a date code for June 1977. If your bike has a White sticker on the headstock for approx July/Aug 1977 then you will know that this is the original lock. There will also be date codes on your other 2 locks.

your best bet might be to bite the bullet and get a new set from Z Power
https://www.z-power.co.uk/lock-assy-z9001000

So my questions are firstly, would the key for the ignition or steering lock originally have fitted the seat lock? Yes (assuming it is a KZ1000 and not a Z1000) Secondly, does the L29 reference relate to a specific key? no.(but I can only say that based on my Z1 knowledge and not KZ1000) And thirdl...

Looks like Sept 1971 which would make it from an H1 / H2. What front hub is it fitted to?

should be a shallow boss on the sprocket. The boss needs to be inward facing to keep the O-ring chain spaced correctly away from the casing. Can't see any boss on your sprocket so might be a Z1 (non-O-ring chain) sprocket. You've also had the chain too loose which is the cause of the 2 scars on the ...

If you know a turner, you can make one. CMSNL have conveniently provided dimensions

Can't tell you size but is this the part you need? Relatively cheap and available.
https://www.cmsnl.com/products/gasket-f ... _92065081/

I'm no expert on later heads but it looks like your 1974 pic (TK-4) maybe has a Z1000 head fitted? Has a 8mm to 6mm stepped stud been used?

The TK-2 castings were generally used on the earlier Z1 range. I have never seen one on a 1975 Z1B but that's not to say old stock was being used up

There are many slight variations on the Z1 heads. Picture here might help you. You can see it if you look carefully by the exhausts

Beautiful. A credit to you

For the more anally inclined........