Snapshot & Restore failing while restoring indices from ES 1.6.1 to ES 2.1.2

Elastic Stack Elasticsearch
3

Thanks for the reply @dadoonet
I have filed an issue: https://github.com/elastic/elasticsearch-migration/issues/56
But it still doesn't seem to solve the problem, even though I create a mapping for .percolator type without _id field on ES 1.6.1; elasticsearch creates one.
For example:
My .percolator mapping

{ 
    ".percolator" : {
    "_routing" : {
      "required" : true
    },
    "_timestamp" : {
      "enabled" : true
    },
	"properties" : {
			"percolator_id"       : { "type" : "string", "index" : "not_analyzed", "include_in_all" : false },
			"oid"                 : { "type" : "integer" },
			"user_id"             : { "type" : "integer" },

			"query"               : { "type" : "object", "enabled" : false }
		}
	}
}

ES 1.6.1 creates a mapping with:

{
  "stage-index-1": {
    "mappings": {
      ".percolator": {
        "_id": {
          "index": "not_analyzed"
        },
        "_routing": {
          "required": true
        },
        "_timestamp": {
          "enabled": true
        },
        "properties": {
          "oid": {
            "type": "integer",
            "doc_values": true
          },
          "percolator_id": {
            "type": "string",
            "index": "not_analyzed",
            "include_in_all": false
          },
          "query": {
            "type": "object",
            "enabled": false
          },
          "user_id": {
            "type": "integer"
          }
        }
      }
    }
  }
}

Note the _id being created in the mapping.
So my guess is because _id is created by default for .percolator documents in earlier versions it is preventing me to restore snapshot to ES 2.1.2 version.

Please let me know if there is any workaround.