How to restore a deleted multipolygon from its members?

Yesterday I created a multipolygon showing the coverage of high-resolution Bing images in Indonesia (, in changesets and Shortly afterwards, another user happened to delete the multipolygon; its members seem to be still present.
Is there an easy way to restore or re-create the multipolygon (in JOSM or another tool)?

Hi Bernhard,

I’m not sure about the capabilities of JOSM’s undelete plugin, but this might help: