Sorry mate, forgot Yahoo Japan links won't open in the UK, Japan side problem, very annoying when I'm in th UK.
https://buyee.jp/item/yahoo/auction/g1172655880?conversionType=YahooAuction_DirectSearch
See how you go with this link. Again in Japanese.
https://auctions.yahoo.co.jp/jp/auction/g1172655880
Not exactly what you're looking for but NOS and comes with an unused rotor. Link is in Japanese sorry.
Though I'd chuck both sets of suspension in the bin that is an absolutely classic FSR Comp in original condition so I could understand if you wanted to keep it like it is. If, however, you did want to take that Coupe Deluxe and shove it up Mr Rockshox's fundamental orifice for making such a...
Do you have these foot nuts? You need a 15mm socket and an extension to get them on (or off). I think the z3.5 only had 80mm of travel so they should look similar to these z4s.
The reason you can't find any info on them is probably because they were OEM only forks for the first gen Specialized P3. I doubt very much there are any spare parts for these specific forks out there but I do see them come up for sale every now and then so you might be able to Frankenstein some.
I've got one of those Sunshine big (50T) cassettes on one of my bikes. Thought I was getting a Sunrace as part of a group set but concede I may not have checked what I was getting thoroughly enough. It's lasted well (2 years) and shifts decently. Me no complain.