You can flash the W200 CID52 firmware to a K510 CID49 WITHOUT upgrading the CID. It will work I'm sure. E.g. A while ago I converted my brother's K310 CID49 to W200 without CID upgrade and works just fine.
However I don't recommend the K510@W200 cross flashing, because you will loose the bluetooth, the camera will not work properly... You will get Walkman player and flash menu. But it's your choice ;)