Yeah, it's been at least 20 years (probably 30 as I think that was 9000 series and not recording custom series) since they had a chrome wrap...If you just need great shells, the stage custom birch line is indistinguishable sonically from the RC line. All birch, made on similar equipment (Yamaha copied the Sakae equipment) angled ply seams etc. Great drums.Then you need to find wrap, which I believe was stainless steel back then. Peral (and others I'm sure) used a chromed plastic wrap as well but I don't know if it would match the metal wrap. And finally, "high tension" lugs, or the 9000 lugs (tail light style).Good luck finding those! The larger sizes are your friend as it was the big, deep drum era I last saw these... 15's are unusual however.
Just a small addition, Air Seal System was the invention of Yamaha from the start (1967) which they used in the Sakae factory in Nittsu/Hamamatsu.
They've installed these in all their factories over the year (Japan, Taiwan, UK and now China)
The Birch Custom is an excellent replacement set, and you could wrap these (or have these wrapped) in a chrome wrap if you'd want.
A 26'' kick size hasn't been made in a very long time, 15'' hanging toms are out of the picture for quite some time too. 16'' toms can be found widely.
Sometimes the ''orphan'' shells you seek do pop up second hand (eBay, Reverb, Craig's List, etc)
Good luck!