air box

I'm having a bit of a clear out, all items can be collected from North London, N14 Later Style hub caps, one fitting snapped (as per photo) but secures fine £18 (includes postage) Bonner air-vent - Part number 706815082 £12 (includes postage) Bonnet insulation - this has been folded in...

My air box has a crack in it and I'm finidng it difficult to locate an a reolacement (Does anyone have one lurking in their garage?) Anyway I got to wondering if I could put an alternative on? I'm thinking something like this...