hI L.A.B
It could well be anything is possible it dosnt actualy match but you may be right for some reson i recon it is from a Villiers engined motor cycle dont ask why just a gut feeling. the closest match ive found so far is from a a old exelsior but top stays dont match up and the centre is just plain on them.Not sure if you can tell from the pictures but it isnt one piece of metal it is three centre part then two sides are welded in place top stays bolt on bottom ones are also welded .
John