Manifold is sold. I still have the spare turbo as well as the stock greddy downpipe.

$160 shipped for turbo, $50 shipped for downpipe.

which manifold is sold? both?

Yes, both manifolds are sold.

As far as bolting on a T28, here's some interesting info:

https://www.miataturbo.net/diy-turbo...t25-t28-63926/

Dunno how it works the other way around though.

Manifold shipped.