I don't see any issues with that, although there's no point-and-click way in OVMM to do that. However, you can always shutdown the guest on the current host and just copy the virtual disk file over to the older OVM and re-setup the guest there again. In the end, it's always the virtual disks that matter, as the vm config can be easily be recreated in the manager gui.
I think that OVM 2.2.1 would just "import" new objects, even if they have been copied onto the SR, when performing a SR scan, but you can also go the standard route and put the virtual disk from the OVM 3.2.1 SR on some http server and import it using the the repo controls in OVM 2.x. However, you might want to change the file name of the virtual disk you copied before you do that since it then will be much easier to spot after importing.