TOPIC:

I don't know the relative strength of the materials used but if Buchanan is telling me to shoot for  40 to 50 inch pounds (front or rear) and the Z1 manual says 28 inch pounds for their zinc/steel spokes, one could safely assume the Buchanan stainless spokes and nipples are stronger. It is just an assumption in the absence of actual tensile strength numbers.
For my purposes the big issue is corrosion. I could put all the effort into re-spoking my rims with zinc/steel, make a few excursions here on Maui and I'd be looking at spokes with white corrosion starting. 
Stainless is a must for me.
 

Is Buchanan's SS spokes superior to OE Kawasaki?

It depends on the grade and diameter of original spokes vs grade and diameter of stainless spokes, typically carbon steel is stronger then stainless, torque examples -
3/8-16 bolt 26 lbs (grade 5)
3/8-16 bolt 37 lbs (grade 8)
3/8-16 bolt 20 lbs (18-8 stainless)
3/8-16 bolt 20 lbs (316 stainless)

Finally found a set of tires. 
Duro 317 and 318
Ive never used Duro but the reviews are generally ok. I need to get this frame up on wheels so this is it for now. Revzilla is sending them here.
I think Duro is a Taiwan company.

I'm in a bit of a slowdown here waiting for some stuff. In the mean time I tackled my switch gear. They were not stock, a little rough but the wiring was ok and the switch contacts inside were ok so I took a shot at cleaning them up. Glass bead blasted, painted and re-assembled, I'll try them out. I'm not sure I could ever find NOS replacements so I thought I'd see if these re-pops are still ok to use.
Glass beads are my friend. They don't tear up the alloy, they just clean it, if a bit slowly.

I've rebuilt a couple over time.  I use paint sticks for the letters, a trick I think I learned from slmjim.  Originals have date codes so you might be out of luck to get something properly date coded for your machine.  I have a friend who restored S/N 1006.  I'll ask him if he has anything kicking around.

Thank you!

I sent him an email yesterday...waiting for his reply.  

Update...Kevin got back to me.  He's apparently sold all his Z1 stuff to someone in Japan.  Crikey!  He had a couple of dozen engines, lots of other parts and about a dozen bikes.  He says he's down to two early Z1's and the stuff he needs to restore them.  One is apparently an original condition one owner bike from Alberta.  I've asked him for any leads and will update if he can provide any help.

Thank you
i guess lots of folks in Japan want Z1 stuff.

I started on front brakes.
First I bead blasted as much as I could. The PO had put lots of paint over the corrosion. Then I pumped the piston out. Fluid looked like mud. Lots of work to do here. I was going to dual disc it but I decided to keep it single. I’ll rebuild the MC and caliper. I have to get a repro disc because again, the PO got rid of the original disc.
the hoses will need to be replaced, lots of cracking. The pipe is pretty corroded too.

Soak that caliper in boiling water for 5 - 10 minutes.  Then apply air pressure to the brake line input.  Use welding gloves and a rag - the piston will pop out with some speed!

I think its a bit late for this, but my go-to method for removing a suck piston is to pump grease in via the bleed nipple.  The pressure slowly and safely pushes the piston out.

Apparently my buddy's controls went to Britain.  He suggested checking the forums over there.  I'm heading down to use his vapour blaster on Saturday.  Will check around his shop to see what he still has left laying around.

You have a good chance of finding a proper date coded brake disc on ebay because they used the same discs on the H1 and H2.  Lots of them for sale.  Just keep looking until one comes up.