I have polymer for them.
Your setup IS for a 180+ rider I think, very stiff anyway.
There was the slender long red, a blue, 2 whites, 2 yellows for 135-145.
You could also slice a thin doughnut of poly and "preload" the stack.
You don't want a white against the slender red, it gets crushed to easily.
You can use PDS polymer, and get better performance.
I have a couple of brand new Inversions, or near new have to dig them out to know for sure. I knew Steve Wilson, was in the warehouse, during new, rebuild / repairing of both forks and bought a ton of spare Halson poly & boots, and about 10 forks when they closed the doors. Their technology was hi-Judy-jacked, as I understood they won a lawsuit against RS but the tech was changed and they had to re-sue them. I never heard from Steve how it turned out the second round. I have his brother's number somewhere but they were pretty bummed at the close of their bike shop chain and of the fork company due to multiple issues.
I had the Marble Peak Sherwood traded fror a handful of forks that sealed an early deal between them (first deal I think) and a buddy still rides it until I can have it back. I even have the stand and a upended pipe attached they used in the fork warehouse. :O) At that tiem, there was no fork that would hold up well, especially for the tandems, except for the Halson Inversion. I will try to dig out the manuals, I have a PDS manual I am pretty sure.
There was a 3rd party boot at some point but I am not sure if it was a mod or direct fit. Steve had boxes of stuff in the late 90's but not sure where he went, and lost touch with his brother as well. Great guys.
His dad started a road bike company like Raleigh, or something, and was later into fitness equipment I think and his brother was a BMX'er so they had biking in their blood.
Grease I always used was the ol standby teflon headset / bike grease and it did not seem to damage the boots.
The black boots were inferior, and cracked early but the PDS boots were much more durable.
A company in Taiwan was building the stuff, I should try to get hold of them and see if we can get enough interest to make some stuff up. They had designs for some great stuff on paper I got to peek at, wish it would have been build...
Aircraft epoxy holds the bonded parts together.
The black top cap on the skewers turned gold if exposed to too much sunlight. The long U-clips can cut the boots so make sure you out them on the least damaging direction.
Keep them clean and lube the bearing surfaces and they last almost indefinitely.
Hope that helps fill the info void a little.