Treasure or Trash! Can anybody identify rusty object found in back garden?

Does anybody know what this curious-looking object is? 

It was found in a back garden in Kildare Town this week - and has baffled the finder.

It could be a priceless artefact or just a rusty piece off an old lawnmower!

It appears to be a small part of something bigger.

Suggestions offered already include:

* A device to quench lighted candles in a church;

* Something to do with a sewing machine.

Somebody must know! What do you think? Any ideas?