|By removing the plates, normally called platters, from the hard disk you have as good as rendered them useless.|
If you really wanted the data from the disk you should have sent the intact disk away. If it was necessary to open the disk and remove the platters it would have been done in a "clean room", environment free of even the tiniest bit of contamination.
By exposing the platters to a normal environment you have made any data recovery that much hard, probably impossible. There is no way that you a user can recover the that now that you have removed the platters from the case.
They platters would need to be remounted and balanced to a high degree of accuracy with tools that you would only find in a manufacturing facility.