Hi Paul -
Other than this
novelty diesel conversion, I don't know of anyone who has actually gone through with a Metro based diesel swap.
It's a Changfa 10hp peak mill, and I think he may need to optimize things a wee bit more.
Besides that one, I get regular hits at MetroMPG.com from a thread at a TDI forum because someone there was also considering a Metro diesel swap, but if you check the thread, you'll see it generated a lot of discussion, but no results:
http://forums.tdiclub.com/showthread.php?t=161256
Are you only going to use the Metro for a conversion, or will you drive it as a gasser?
And... welcome to the site!